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The Bone & Joint Journal
Vol. 95-B, Issue 2 | Pages 177 - 180
1 Feb 2013
Arthur CHC Wood AM Keenan ACM Clayton RAE Walmsley P Brenkel I

We report ten-year clinical and radiological follow-up data for the Sigma Press Fit Condylar total knee replacement system (Sigma PFC TKR). Between October 1998 and October 1999 a total of 235 consecutive PFC Sigma TKRs were carried out in 203 patients. Patients were seen at a specialist nurse-led clinic seven to ten days before admission and at six and 18 months, three, five and eight to ten years after surgery. Data were recorded prospectively at each clinic visit. Radiographs were obtained at the five- and eight- to ten-year follow-up appointments. Of the 203 patients, 147 (171 knees) were alive at ten years and 12 were lost to follow-up. A total of eight knees (3.4%) were revised, five for infection and three to change the polyethylene insert. The survival at ten years with an endpoint of revision for any reason was 95.9%, and with an endpoint of revision for aseptic failure was 98.7%. The mean American Knee Society Score (AKSS) was 79 (10 to 99) at eight to ten years, compared with 31 (2 to 62) pre-operatively. Of 109 knee with radiographs reviewed, 47 knees had radiolucent lines but none showed evidence of loosening. Cite this article: Bone Joint J 2013;95-B:177–80


The Bone & Joint Journal
Vol. 100-B, Issue 10 | Pages 1336 - 1344
1 Oct 2018
Powell AJ Crua E Chong BC Gordon R McAuslan A Pitto RP Clatworthy MG

Aims

This study compares the PFC total knee arthroplasty (TKA) system in a prospective randomized control trial (RCT) of the mobile-bearing rotating-platform (RP) TKA against the fixed-bearing (FB) TKA. This is the largest RCT with the longest follow-up where cruciate-retaining PFC total knee arthroplasties are compared in a non-bilateral TKA study.

Patients and Methods

A total of 167 patients (190 knees with 23 bilateral cases), were recruited prospectively and randomly assigned, with 91 knees receiving the RP and 99 knees receiving FB. The mean age was 65.5 years (48 to 82), the mean body mass index (BMI) was 29.7 kg/m2 (20 to 52) and 73 patients were female. The Knee Society Score (KSS), Knee Society Functional Score (KSFS), Oxford Knee Score (OKS), Western Ontario and McMaster Universities Arthritis Index (WOMAC), and 12-Item Short-Form Health Survey Physical and Mental Component Scores (SF-12 PCS, SF-12 MCS) were gathered and recorded preoperatively, at five-years’ follow-up, and at ten years’ follow-up. Additionally, Knee Injury and Osteoarthritis Outcome Scores (KOOS) were collected at five- and ten-year follow-ups. The prevalence of radiolucent lines (RL) on radiographs and implant survival were recorded at five- and ten-year follow-ups.


The Journal of Bone & Joint Surgery British Volume
Vol. 90-B, Issue 12 | Pages 1594 - 1596
1 Dec 2008
Dalury DF Barrett WP Mason JB Goldstein WM Murphy JA Roche MW

This retrospective study evaluated the midterm clinical and radiographic outcomes of a second-generation total knee replacement system. In a multicentre consecutive series of 1512 patients, 1970 knees were treated with the PFC Sigma knee system (Depuy, Warsaw, Indiana). The patients were reviewed for functional outcome, and underwent independent radiographic evaluation at a mean follow-up of 7.3 years (5 to 10). A total of 40 knees (2%) required revision, 17 (0.9%) for infection. The incidence of osteolysis was 2.2%. The ten-year survival with revision for any cause other than infection as the endpoint was 97.2% (95% CI 95.4 to 99.1). The PFC Sigma knee system appears to provide excellent results in the medium term


The Bone & Joint Journal
Vol. 101-B, Issue 7_Supple_C | Pages 48 - 54
1 Jul 2019
Kahlenberg CA Lyman S Joseph AD Chiu Y Padgett DE

Aims. The outcomes of total knee arthroplasty (TKA) depend on many factors. The impact of implant design on patient-reported outcomes is unknown. Our goal was to evaluate the patient-reported outcomes and satisfaction after primary TKA in patients with osteoarthritis undergoing primary TKA using five different brands of posterior-stabilized implant. Patients and Methods. Using our institutional registry, we identified 4135 patients who underwent TKA using one of the five most common brands of implant. These included Biomet Vanguard (Zimmer Biomet, Warsaw, Indiana) in 211 patients, DePuy/Johnson & Johnson Sigma (DePuy Synthes, Raynham, Massachusetts) in 222, Exactech Optetrak Logic (Exactech, Gainesville, Florida) in 1508, Smith & Nephew Genesis II (Smith & Nephew, London, United Kingdom) in 1415, and Zimmer NexGen (Zimmer Biomet) in 779 patients. Patients were evaluated preoperatively using the Knee Injury and Osteoarthritis Outcome Score (KOOS), Lower Extremity Activity Scale (LEAS), and 12-Item Short-Form Health Survey questionnaire (SF-12). Demographics including age, body mass index, Charlson Comorbidity Index, American Society of Anethesiologists status, sex, and smoking status were collected. Postoperatively, two-year KOOS, LEAS, SF-12, and satisfaction scores were compared between groups. Results. Outcomes were available for 4069 patients (98%) at two years postoperatively. In multiple regression analysis, which separately compared each implant group with the aggregate of all others, there were no clinically significant differences in the change of KOOS score from baseline to two-year follow-up between any of the groups. More than 80% of patients in each group were satisfied at this time in all domains. In a multivariate regression model, patients in the NexGen group were the most likely to be satisfied (odds ratio (OR) 1.63; p = 0.006) and Optetrak Logic patients were the least likely to be satisfied (OR 0.60; p < 0.001). Conclusion. TKA provides improvement in function and satisfaction regardless of the type of implant. We could not demonstrate superiority of one design above others across these groups of implants, and any price premium for one above the other systems may not be justified. Healthcare administrators may find these similarities in outcomes helpful when negotiating purchasing contracts. Cite this article: Bone Joint J 2019;101-B(7 Supple C):48–54


The Bone & Joint Journal
Vol. 105-B, Issue 6 | Pages 610 - 621
1 Jun 2023
Prodromidis AD Chloros GD Thivaios GC Sutton PM Pandit H Giannoudis PV Charalambous CP

Aims

Loosening of components after total knee arthroplasty (TKA) can be associated with the development of radiolucent lines (RLLs). The aim of this study was to assess the rate of formation of RLLs in the cemented original design of the ATTUNE TKA and their relationship to loosening.

Methods

A systematic search was undertaken using the Cochrane methodology in three online databases: MEDLINE, Embase, and CINAHL. Studies were screened against predetermined criteria, and data were extracted. Available National Joint Registries in the Network of Orthopaedic Registries of Europe were also screened. A random effects model meta-analysis was undertaken.


The Bone & Joint Journal
Vol. 106-B, Issue 11 | Pages 1240 - 1248
1 Nov 2024
Smolle MA Keintzel M Staats K Böhler C Windhager R Koutp A Leithner A Donner S Reiner T Renkawitz T Sava M Hirschmann MT Sadoghi P

Aims

This multicentre retrospective observational study’s aims were to investigate whether there are differences in the occurrence of radiolucent lines (RLLs) following total knee arthroplasty (TKA) between the conventional Attune baseplate and its successor, the novel Attune S+, independent from other potentially influencing factors; and whether tibial baseplate design and presence of RLLs are associated with differing risk of revision.

Methods

A total of 780 patients (39% male; median age 70.7 years (IQR 62.0 to 77.2)) underwent cemented TKA using the Attune Knee System) at five centres, and with the latest radiograph available for the evaluation of RLL at between six and 36 months from surgery. Univariate and multivariate logistic regression models were performed to assess associations between patient and implant-associated factors on the presence of tibial and femoral RLLs. Differences in revision risk depending on RLLs and tibial baseplate design were investigated with the log-rank test.


The Journal of Bone & Joint Surgery British Volume
Vol. 94-B, Issue 7 | Pages 928 - 931
1 Jul 2012
Keenan ACM Wood AM Arthur CA Jenkins PJ Brenkel IJ Walmsley PJ

We report the ten-year survival of a cemented total knee replacement (TKR) in patients aged < 55 years at the time of surgery, and compare the functional outcome with that of patients aged > 55 years. The data were collected prospectively and analysed using Kaplan-Meier survival statistics, with revision for any reason, or death, as the endpoint. A total of 203 patients aged < 55 years were identified. Four had moved out of the area and were excluded, leaving a total of 221 TKRs in 199 patients for analysis (101 men and 98 women, mean age 50.6 years (28 to 55)); 171 patients had osteoarthritis and 28 had inflammatory arthritis. Four patients required revision and four died. The ten-year survival using revision as the endpoint was 98.2% (95% confidence interval 94.6 to 99.4). Based on the Oxford knee scores at five and ten years, the rate of dissatisfaction was 18% and 21%, respectively. This was no worse in the patients aged < 55 years than in patients aged > 55 years. These results demonstrate that the cemented PFC Sigma knee has an excellent survival rate in patients aged < 55 ten years post-operatively, with clinical outcomes similar to those of an older group. We conclude that TKR should not be withheld from patients on the basis of age


The Journal of Bone & Joint Surgery British Volume
Vol. 94-B, Issue 8 | Pages 1051 - 1057
1 Aug 2012
Nutton RW Wade FA Coutts FJ van der Linden ML

This prospective randomised controlled double-blind trial compared two types of PFC Sigma total knee replacement (TKR), differing in three design features aimed at improving flexion. The outcome of a standard fixed-bearing posterior cruciate ligament-preserving design (FB-S) was compared with that of a high-flexion rotating-platform posterior-stabilised design (RP-F) at one year after TKR. The study group of 77 patients with osteoarthritis of the knee comprised 37 men and 40 women, with a mean age of 69 years (44.9 to 84.9). The patients were randomly allocated either to the FB-S or the RP-F group and assessed pre-operatively and at one year post-operatively. The mean post-operative non-weight-bearing flexion was 107° (95% confidence interval (CI) 104° to 110°)) for the FB-S group and 113° (95% CI 109° to 117°) for the RP-F group, and this difference was statistically significant (p = 0.032). However, weight-bearing range of movement during both level walking and ascending a slope as measured during flexible electrogoniometry was a mean of 4° lower in the RP-F group than in the FB-S group, with 58° (95% CI 56° to 60°) versus 54° (95% CI 51° to 57°) for level walking (p = 0.019) and 56° (95% CI 54° to 58°) versus 52° (95% CI 48° to 56°) for ascending a slope (p = 0.044). Further, the mean post-operative pain score of the Western Ontario and McMaster Universities Osteoarthritis Index was significantly higher in the RP-F group (2.5 (95% CI 1.5 to 3.5) versus 4.2 (95% CI 2.9 to 5.5), p = 0.043). Although the RP-F group achieved higher non-weight-bearing knee flexion, patients in this group did not use this during activities of daily living and reported more pain one year after surgery


The Bone & Joint Journal
Vol. 105-B, Issue 6 | Pages 622 - 634
1 Jun 2023
Simpson CJRW Wright E Ng N Yap NJ Ndou S Scott CEH Clement ND

Aims

This systematic review and meta-analysis aimed to compare the influence of patellar resurfacing following cruciate-retaining (CR) and posterior-stabilized (PS) total knee arthroplasty (TKA) on the incidence of anterior knee pain, knee-specific patient-reported outcome measures, complication rates, and reoperation rates.

Methods

A systematic review of MEDLINE, PubMed, and Google Scholar was performed to identify randomized controlled trials (RCTs) according to search criteria. Search terms used included: arthroplasty, replacement, knee (Mesh), TKA, prosthesis, patella, patellar resurfacing, and patellar retaining. RCTs that compared patellar resurfacing versus unresurfaced in primary TKA were included for further analysis. Studies were evaluated using the Scottish Intercollegiate Guidelines Network assessment tool for quality and minimization of bias. Data were synthesized and meta-analysis performed.


The Journal of Bone & Joint Surgery British Volume
Vol. 91-B, Issue 5 | Pages 604 - 611
1 May 2009
Reay E Wu J Holland J Deehan D

We describe a cohort of patients with a high rate of mid-term failure following Kinemax Plus total knee replacement inserted between 1998 and 2001. This implant has been recorded as having a survival rate of 96% at ten years. However, in our series the survival rate was 75% at nine years. This was also significantly lower than that of subsequent consecutive series of PFC Sigma knee replacements performed by the same surgeon. No differences were found in the clinical and radiological parameters between the two groups. At revision the most striking finding was polyethylene wear. An independent analysis of the polyethylene components was therefore undertaken. Scanning electron microscopy revealed type 2 fusion defects in the ultra-high molecular weight polyethylene (UHMWPE), which indicated incomplete boundary fusion. Other abnormalities consistent with weak UHMWPE particle interface strength were present in both the explanted inserts and in unused inserts from the same period. We consider that these type 2 fusion defects are the cause of the early failure of the Kinemax implants. This may represent a manufacturing defect resulting in a form of programmed polyethylene failure


The Journal of Bone & Joint Surgery British Volume
Vol. 94-B, Issue 7 | Pages 937 - 940
1 Jul 2012
Manopoulos P Havet E Pearce O Lardanchet JF Mertl P

This was a retrospective analysis of the medium- to long-term results of 46 TC3 Sigma revision total knee replacements using long uncemented stems in press-fit mode. Clinical and radiological analysis took place pre-operatively, at two years post-operatively, and at a mean follow-up of 8.5 years (4 to 12). The mean pre-operative International Knee Society (IKS) clinical score was 42 points (0 to 74), improving to 83.7 (52 to 100) by the final follow-up. The mean IKS score for function improved from 34.3 points (0 to 80) to 64.2 (15 to 100) at the final follow-up. At the final follow-up 30 knees (65.2%) had an excellent result, seven (15.2%) a good result, one (2.2%) a medium and eight (17.4%) a poor result. There were two failures, one with anteroposterior instability and one with aseptic loosening. The TC3 revision knee system, when used with press-fit for long intramedullary stems and cemented femoral and tibial components, in both septic and aseptic revisions, results in a satisfactory clinical and radiological outcome, and has a good medium- to long-term survival rate


The Journal of Bone & Joint Surgery British Volume
Vol. 91-B, Issue 7 | Pages 903 - 906
1 Jul 2009
Trickett RW Hodgson P Forster MC Robertson A

We aimed to determine the reliability, accuracy and the clinical role of digital templating in the pre-operative work-up for total knee replacement. Initially a sample of ten pre-operative digital radiographs were templated by four independent observers to determine the inter- and intra-observer reliability of the process. Digital templating was then performed on the radiographs of 40 consecutive patients undergoing total knee replacement by a consultant surgeon not involved with the operation, who was blinded to the size of the implant inserted. The Press Fit Condylar Sigma Knee system was used in all the patients. The size of the implant as judged by templating was then compared to that of the size used. Good inter- and intra-observer agreement was demonstrated for both femoral and tibial templating. However, the correct size of the implant was predicted in only 48% of the femoral and 55% of the tibial components. Albeit reproducible, digital templating does not currently predict the correct size of component often enough to be of clinical benefit


The Journal of Bone & Joint Surgery British Volume
Vol. 91-B, Issue 3 | Pages 357 - 360
1 Mar 2009
Dalury DF Mason JB Murphy JA Adams MJ

Gender-specific total knee replacement has generated much interest recently. We reviewed 1970 Sigma knees implanted in 920 women and 592 men with a mean age of 69.7 years. At a mean follow-up of 7.3 years (minimum, five years), we found minimal differences in the outcome between genders. At the final follow-up, men had a higher overall Knee Society score and more osteolysis (3.8% vs 1.1%). However, there were no significant differences between men and women in terms of complications or improvements in knee function, pain score or range of movement. The estimated ten-year survivorship was 97% in women and 98% in men (p = 0.96). We concluded that there was little difference in outcome between the genders treated by a modern unisex design of total knee replacement in this large multicentre study


The Bone & Joint Journal
Vol. 104-B, Issue 10 | Pages 1126 - 1131
1 Oct 2022
Hannon CP Kruckeberg BM Pagnano MW Berry DJ Hanssen AD Abdel MP

Aims

We have previously reported the mid-term outcomes of revision total knee arthroplasty (TKA) for flexion instability. At a mean of four years, there were no re-revisions for instability. The aim of this study was to report the implant survivorship and clinical and radiological outcomes of the same cohort of of patients at a mean follow-up of ten years.

Methods

The original publication included 60 revision TKAs in 60 patients which were undertaken between 2000 and 2010. The mean age of the patients at the time of revision TKA was 65 years, and 33 (55%) were female. Since that time, 21 patients died, leaving 39 patients (65%) available for analysis. The cumulative incidence of any re-revision with death as a competing risk was calculated. Knee Society Scores (KSSs) were also recorded, and updated radiographs were reviewed.


The Bone & Joint Journal
Vol. 106-B, Issue 9 | Pages 1021 - 1030
1 Sep 2024
Oto J Herranz R Fuertes M Plana E Verger P Baixauli F Amaya JV Medina P

Aims

Bacterial infection activates neutrophils to release neutrophil extracellular traps (NETs) in bacterial biofilms of periprosthetic joint infections (PJIs). The aim of this study was to evaluate the increase in NET activation and release (NETosis) and haemostasis markers in the plasma of patients with PJI, to evaluate whether such plasma induces the activation of neutrophils, to ascertain whether increased NETosis is also mediated by reduced DNaseI activity, to explore novel therapeutic interventions for NETosis in PJI in vitro, and to evaluate the potential diagnostic use of these markers.

Methods

We prospectively recruited 107 patients in the preoperative period of prosthetic surgery, 71 with a suspicion of PJI and 36 who underwent arthroplasty for non-septic indications as controls, and obtained citrated plasma. PJI was confirmed in 50 patients. We measured NET markers, inflammation markers, DNaseI activity, haemostatic markers, and the thrombin generation test (TGT). We analyzed the ability of plasma from confirmed PJI and controls to induce NETosis and to degrade in vitro-generated NETs, and explored the therapeutic restoration of the impairment to degrade NETs of PJI plasma with recombinant human DNaseI. Finally, we assessed the contribution of these markers to the diagnosis of PJI.


The Bone & Joint Journal
Vol. 103-B, Issue 12 | Pages 1791 - 1801
1 Dec 2021
Bhalekar RM Nargol ME Shyam N Nargol AVF Wells SR Collier R Pabbruwe M Joyce TJ Langton DJ

Aims

The aim of this study was to investigate whether wear and backside deformation of polyethylene (PE) tibial inserts may influence the cement cover of tibial trays of explanted total knee arthroplasties (TKAs).

Methods

At our retrieval centre, we measured changes in the wear and deformation of PE inserts using coordinate measuring machines and light microscopy. The amount of cement cover on the backside of tibial trays was quantified as a percentage of the total surface. The study involved data from the explanted fixed-bearing components of four widely used contemporary designs of TKA (Attune, NexGen, Press Fit Condylar (PFC), and Triathlon), revised for any indication, and we compared them with components that used previous generations of PE. Regression modelling was used to identify variables related to the amount of cement cover on the retrieved trays.


The Bone & Joint Journal
Vol. 103-B, Issue 11 | Pages 1695 - 1701
1 Nov 2021
Currier JH Currier BH Abdel MP Berry DJ Titus AJ Van Citters DW

Aims

Wear of the polyethylene (PE) tibial insert of total knee arthroplasty (TKA) increases the risk of revision surgery with a significant cost burden on the healthcare system. This study quantifies wear performance of tibial inserts in a large and diverse series of retrieved TKAs to evaluate the effect of factors related to the patient, knee design, and bearing material on tibial insert wear performance.

Methods

An institutional review board-approved retrieval archive was surveyed for modular PE tibial inserts over a range of in vivo duration (mean 58 months (0 to 290)). Five knee designs, totalling 1,585 devices, were studied. Insert wear was estimated from measured thickness change using a previously published method. Linear regression statistical analyses were used to test association of 12 patient and implant design variables with calculated wear rate.


The Bone & Joint Journal
Vol. 103-B, Issue 6 Supple A | Pages 137 - 144
1 Jun 2021
Lachiewicz PF Steele JR Wellman SS

Aims

To establish our early clinical results of a new total knee arthroplasty (TKA) tibial component introduced in 2013 and compare it to other designs in use at our hospital during the same period.

Methods

This is a retrospective study of 166 (154 patients) consecutive cemented, fixed bearing, posterior-stabilized (PS) TKAs (ATTUNE) at one hospital performed by five surgeons. These were compared with a reference cohort of 511 knees (470 patients) of other designs (seven manufacturers) performed at the same hospital by the same surgeons. There were no significant differences in age, sex, BMI, or follow-up times between the two cohorts. The primary outcome was revision performed or pending.


The Bone & Joint Journal
Vol. 104-B, Issue 4 | Pages 452 - 463
1 Apr 2022
Elcock KL Carter TH Yapp LZ MacDonald DJ Howie CR Stoddart A Berg G Clement ND Scott CEH

Aims

Access to total knee arthroplasty (TKA) is sometimes restricted for patients with severe obesity (BMI ≥ 40 kg/m2). This study compares the cost per quality-adjusted life year (QALY) associated with TKA in patients with a BMI above and below 40 kg/m2 to examine whether this is supported.

Methods

This single-centre study compared 169 consecutive patients with severe obesity (BMI ≥ 40 kg/m2) (mean age 65.2 years (40 to 87); mean BMI 44.2 kg/m2 (40 to 66); 129/169 female) undergoing unilateral TKA to a propensity score matched (age, sex, preoperative Oxford Knee Score (OKS)) cohort with a BMI < 40 kg/m2 in a 1:1 ratio. Demographic data, comorbidities, and complications to one year were recorded. Preoperative and one-year patient-reported outcome measures (PROMs) were completed: EuroQol five-dimension three-level questionnaire (EQ-5D-3L), OKS, pain, and satisfaction. Using national life expectancy data with obesity correction and the 2020 NHS National Tariff, QALYs (discounted at 3.5%), and direct medical costs accrued over a patient’s lifetime, were calculated. Probabilistic sensitivity analysis (PSA) was used to model variation in cost/QALY for each cohort across 1,000 simulations.


The Bone & Joint Journal
Vol. 103-B, Issue 8 | Pages 1373 - 1379
1 Aug 2021
Matar HE Bloch BV Snape SE James PJ

Aims

Single-stage revision total knee arthroplasty (rTKA) is gaining popularity in treating chronic periprosthetic joint infections (PJIs). We have introduced this approach to our clinical practice and sought to evaluate rates of reinfection and re-revision, along with predictors of failure of both single- and two-stage rTKA for chronic PJI.

Methods

A retrospective comparative cohort study of all rTKAs for chronic PJI between 1 April 2003 and 31 December 2018 was undertaken using prospective databases. Patients with acute infections were excluded; rTKAs were classified as single-stage, stage 1, or stage 2 of two-stage revision. The primary outcome measure was failure to eradicate or recurrent infection. Variables evaluated for failure by regression analysis included age, BMI, American Society of Anesthesiologists grade, infecting organisms, and the presence of a sinus. Patient survivorship was also compared between the groups.


The Bone & Joint Journal
Vol. 102-B, Issue 10 | Pages 1331 - 1340
3 Oct 2020
Attard V Li CY Self A Mann DA Borthwick LA O’Connor P Deehan DJ Kalson NS

Aims

Stiffness is a common complication after total knee arthroplasty (TKA). Pathogenesis is not understood, treatment options are limited, and diagnosis is challenging. The aim of this study was to investigate if MRI can be used to visualize intra-articular scarring in patients with stiff, painful knee arthroplasties.

Methods

Well-functioning primary TKAs (n = 11), failed non-fibrotic TKAs (n = 5), and patients with a clinical diagnosis of fibrosis1 (n = 8) underwent an MRI scan with advanced metal suppression (Slice Encoding for Metal Artefact Correction, SEMAC) with gadolinium contrast. Fibrotic tissue (low intensity on T1 and T2, low-moderate post-contrast enhancement) was quantified (presence and tissue thickness) in six compartments: supra/infrapatella, medial/lateral gutters, and posterior medial/lateral.


The Bone & Joint Journal
Vol. 103-B, Issue 7 | Pages 1254 - 1260
1 Jul 2021
Calabro L Clement ND MacDonald D Patton JT Howie CR Burnett R

Aims

The primary aim of this study was to assess whether non-fatal postoperative venous thromboembolism (VTE) within six months of surgery influences the knee-specific functional outcome (Oxford Knee Score (OKS)) one year after total knee arthroplasty (TKA). Secondary aims were to assess whether non-fatal postoperative VTE influences generic health and patient satisfaction at this time.

Methods

A study of 2,393 TKAs was performed in 2,393 patients. Patient demographics, comorbidities, OKS, EuroQol five-dimension score (EQ-5D), and Forgotten Joint Score (FJS) were collected preoperatively and one year postoperatively. Overall patient satisfaction with their TKA was assessed at one year. Patients with VTE within six months of surgery were identified retrospectively and compared with those without.


The Bone & Joint Journal
Vol. 101-B, Issue 8 | Pages 960 - 969
1 Aug 2019
Odgaard A Laursen MB Gromov K Troelsen A Kristensen PW Schrøder H Madsen F Overgaard S

Aims

The aim of this study was to give estimates of the incidence of component incompatibility in hip and knee arthroplasty and to test the effect of an online, real-time compatibility check.

Materials and Methods

Intraoperative barcode registration of arthroplasty implants was introduced in Denmark in 2013. We developed a compatibility database and, from May 2017, real-time compatibility checking was implemented and became part of the registration. We defined four classes of component incompatibility: A-I, A-II, B-I, and B-II, depending on an assessment of the level of risk to the patient (A/B), and on whether incompatibility was knowingly accepted (I/II).


The Bone & Joint Journal
Vol. 103-B, Issue 5 | Pages 864 - 871
3 May 2021
Hunt LP Matharu GS Blom AW Howard PW Wilkinson JM Whitehouse MR

Aims

Debate remains whether the patella should be resurfaced during total knee replacement (TKR). For non-resurfaced TKRs, we estimated what the revision rate would have been if the patella had been resurfaced, and examined the risk of re-revision following secondary patellar resurfacing.

Methods

A retrospective observational study of the National Joint Registry (NJR) was performed. All primary TKRs for osteoarthritis alone performed between 1 April 2003 and 31 December 2016 were eligible (n = 842,072). Patellar resurfacing during TKR was performed in 36% (n = 305,844). The primary outcome was all-cause revision surgery. Secondary outcomes were the number of excess all-cause revisions associated with using TKRs without (versus with) patellar resurfacing, and the risk of re-revision after secondary patellar resurfacing.


The Bone & Joint Journal
Vol. 102-B, Issue 4 | Pages 426 - 433
1 Apr 2020
Boettner F Sculco P Faschingbauer M Rueckl K Windhager R Kasparek MF

Aims

To compare patients undergoing total knee arthroplasty (TKA) with ≤ 80° range of movement (ROM) operated with a 2 mm increase in the flexion gap with matched non-stiff patients with at least 100° of preoperative ROM and balanced flexion and extension gaps.

Methods

In a retrospective cohort study, 98 TKAs (91 patients) with a preoperative ROM of ≤ 80° were examined. Mean follow-up time was 53 months (24 to 112). All TKAs in stiff knees were performed with a 2 mm increased flexion gap. Data were compared to a matched control group of 98 TKAs (86 patients) with a mean follow-up of 43 months (24 to 89). Knees in the control group had a preoperative ROM of at least 100° and balanced flexion and extension gaps. In all stiff and non-stiff knees posterior stabilized (PS) TKAs with patellar resurfacing in combination with adequate soft tissue balancing were used.


The Bone & Joint Journal
Vol. 102-B, Issue 10 | Pages 1375 - 1383
3 Oct 2020
Zhang T Sze KY Peng ZW Cheung KMC Lui YF Wong YW Kwan KYH Cheung JPY

Aims

To investigate metallosis in patients with magnetically controlled growing rods (MCGRs) and characterize the metal particle profile of the tissues surrounding the rod.

Methods

This was a prospective observational study of patients with early onset scoliosis (EOS) treated with MCGRs and undergoing rod exchange who were consecutively recruited between February 2019 and January 2020. Ten patients were recruited (mean age 12 years (SD 1.3); 2 M:8 F). The configurations of the MCGR were studied to reveal the distraction mechanisms, with crucial rod parts being the distractable piston rod and the magnetically driven rotor inside the barrel of the MCGR. Metal-on-metal contact in the form of ring-like wear marks on the piston was found on the distracted portion of the piston immediately outside the barrel opening (BO) through which the piston rod distracts. Biopsies of paraspinal muscles and control tissue samples were taken over and away from the wear marks, respectively. Spectral analyses of the rod alloy and biopsies were performed to reveal the metal constituents and concentrations. Histological analyses of the biopsies were performed with haematoxylin and eosin staining.


The Bone & Joint Journal
Vol. 102-B, Issue 9 | Pages 1158 - 1166
14 Sep 2020
Kaptein BL den Hollander P Thomassen B Fiocco M Nelissen RGHH

Aims

The primary objective of this study was to compare migration of the cemented ATTUNE fixed bearing cruciate retaining tibial component with the cemented Press-Fit Condylar (PFC)-sigma fixed bearing cruciate retaining tibial component. The secondary objectives included comparing clinical and radiological outcomes and Patient Reported Outcome Measures (PROMs).

Methods

A single blinded randomized, non-inferiority study was conducted including 74 patients. Radiostereometry examinations were made after weight bearing, but before hospital discharge, and at three, six, 12, and 24 months postoperatively. PROMS were collected preoperatively and at three, six, 12, and 24 months postoperatively. Radiographs for measuring radiolucencies were collected at two weeks and two years postoperatively.


The Bone & Joint Journal
Vol. 102-B, Issue 6 Supple A | Pages 85 - 90
1 Jun 2020
Blevins JL Rao V Chiu Y Lyman S Westrich GH

Aims

The purpose of this investigation was to determine the relationship between height, weight, and sex with implant size in total knee arthroplasty (TKA) using a multivariate linear regression model and a Bayesian model.

Methods

A retrospective review of an institutional registry was performed of primary TKAs performed between January 2005 and December 2016. Patient demographics including patient age, sex, height, weight, and body mass index (BMI) were obtained from registry and medical record review. In total, 8,100 primary TKAs were included. The mean age was 67.3 years (SD 9.5) with a mean BMI of 30.4 kg/m2 (SD 6.3). The TKAs were randomly split into a training cohort (n = 4,022) and a testing cohort (n = 4,078). A multivariate linear regression model was created on the training cohort and then applied to the testing cohort . A Bayesian model was created based on the frequencies of implant sizes in the training cohort. The model was then applied to the testing cohort to determine the accuracy of the model at 1%, 5%, and 10% tolerance of inaccuracy.


The Bone & Joint Journal
Vol. 102-B, Issue 6 Supple A | Pages 49 - 58
1 Jun 2020
Mullaji A

Aims

The aims of this study were to determine the effect of osteophyte excision on deformity correction and soft tissue gap balance in varus knees undergoing computer-assisted total knee arthroplasty (TKA).

Methods

A total of 492 consecutive, cemented, cruciate-substituting TKAs performed for varus osteoarthritis were studied. After exposure and excision of both cruciates and menisci, it was noted from operative records the corrective interventions performed in each case. Knees in which no releases after the initial exposure, those which had only osteophyte excision, and those in which further interventions were performed were identified. From recorded navigation data, coronal and sagittal limb alignment, knee flexion range, and medial and lateral gap distances in maximum knee extension and 90° knee flexion with maximal varus and valgus stresses, were established, initially after exposure and excision of both cruciate ligaments, and then also at trialling. Knees were defined as ‘aligned’ if the hip-knee-ankle axis was between 177° and 180°, (0° to 3° varus) and ‘balanced’ if medial and lateral gaps in extension and at 90° flexion were within 2 mm of each other.


The Bone & Joint Journal
Vol. 101-B, Issue 7_Supple_C | Pages 77 - 83
1 Jul 2019
James EW Blevins JL Gausden EB Turcan S Denova TA Satalich JR Ranawat AS Warren RF Ranawat AS

Aims

Anterior cruciate ligament (ACL) and multiligament knee (MLK) injuries increase the risk of development of knee osteoarthritis and eventual need for total knee arthroplasty (TKA). There are limited data regarding implant use and outcomes in these patients. The aim of this study was to compare the use of constrained implants and outcomes among patients undergoing TKA with a history of prior knee ligament reconstruction (PKLR) versus a matched cohort of patients undergoing TKA with no history of PKLR.

Patients and Methods

Patients with a history of ACL or MLK reconstruction who underwent TKA between 2007 and 2017 were identified in a single-institution registry. There were 223 patients who met inclusion criteria (188 ACL reconstruction patients, 35 MLK reconstruction patients). A matched cohort, also of 223 patients, was identified based on patient age, body mass index (BMI), sex, and year of surgery. There were 144 male patients and 79 female patients in both cohorts. Mean age at the time of TKA was 57.2 years (31 to 88). Mean BMI was 29.7 kg/m2 (19.5 to 55.7).


The Bone & Joint Journal
Vol. 102-B, Issue 3 | Pages 310 - 318
1 Mar 2020
Joseph MN Achten J Parsons NR Costa ML

Aims

A pragmatic, single-centre, double-blind randomized clinical trial was conducted in a NHS teaching hospital to evaluate whether there is a difference in functional knee scores, quality-of-life outcome assessments, and complications at one-year after intervention between total knee arthroplasty (TKA) and patellofemoral arthroplasty (PFA) in patients with severe isolated patellofemoral arthritis.

Methods

This parallel, two-arm, superiority trial was powered at 80%, and involved 64 patients with severe isolated patellofemoral arthritis. The primary outcome measure was the functional section of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score at 12 months. Secondary outcomes were the full 24-item WOMAC, Oxford Knee Score (OKS), American Knee Society Score (AKSS), EuroQol five dimension (EQ-5D) quality-of-life score, the University of California, Los Angeles (UCLA) Physical Activity Rating Scale, and complication rates collected at three, six, and 12 months. For longer-term follow-up, OKS, EQ-5D, and self-reported satisfaction score were collected at 24 and 60 months.


Aims

The aim is to assess the cost-effectiveness of patellofemoral arthroplasty (PFA) in comparison with total knee arthroplasty (TKA) for the treatment of isolated patellofemoral osteoarthritis (OA) based on prospectively collected data on health outcomes and resource use from a blinded, randomized, clinical trial.

Methods

A total of 100 patients with isolated patellofemoral osteoarthritis were randomized to receive either PFA or TKA by experienced knee surgeons trained in using both implants. Patients completed patient-reported outcomes including EuroQol five-dimension questionnaire (EQ-5D) and 6-Item Short-Form Health Survey questionnaire (SF-6D) before the procedure. The scores were completed again after six weeks, three, six, and nine months, and again after one- and two-year post-surgery and yearly henceforth. Time-weighted outcome measures were constructed. Cost data were obtained from clinical registrations and patient-reported questionnaires. Incremental gain in health outcomes (quality-adjusted life-years (QALYs)) and incremental costs were compared for the two groups of patients. Net monetary benefit was calculated assuming a threshold value of €10,000, €35,000, and €50,000 per QALY and used to test the statistical uncertainty and central assumptions about outcomes and costs.


The Bone & Joint Journal
Vol. 102-B, Issue 3 | Pages 319 - 328
1 Mar 2020
St Mart J de Steiger RN Cuthbert A Donnelly W

Aim

There has been a significant reduction in unicompartmental knee arthroplasty (UKA) procedures recorded in Australia. This follows several national joint registry studies documenting high UKA revision rates when compared to total knee arthroplasty (TKA). With the recent introduction of robotically assisted UKA procedures, it is hoped that outcomes improve. This study examines the cumulative revision rate of UKA procedures implanted with a newly introduced robotic system and compares the results to one of the best performing non-robotically assisted UKA prostheses, as well as all other non-robotically assisted UKA procedures.

Methods

Data from the Australian Orthopaedic Association National Joint Arthroplasty Registry (AOANJRR) for all UKA procedures performed for osteoarthritis (OA) between 2015 and 2018 were analyzed. Procedures using the Restoris MCK UKA prosthesis implanted using the Mako Robotic-Arm Assisted System were compared to non-robotically assisted Zimmer Unicompartmental High Flex Knee System (ZUK) UKA, a commonly used UKA with previously reported good outcomes and to all other non-robotically assisted UKA procedures using Cox proportional hazard ratios (HRs) and Kaplan-Meier estimates of survivorship.


The Bone & Joint Journal
Vol. 101-B, Issue 11 | Pages 1356 - 1361
1 Nov 2019
Chalmers BP Mehrotra KG Sierra RJ Pagnano MW Taunton MJ Abdel MP

Aims

Knee osteonecrosis in advanced stages may lead to joint degeneration. Total knee arthroplasty (TKA) for osteonecrosis has traditionally been associated with suboptimal results. We analyzed outcomes of contemporary TKAs for osteonecrosis, with particular emphasis on: survivorship free from aseptic loosening, any revision, and any reoperation plus the clinical outcomes, complications, and radiological results.

Patients and Methods

In total, 156 patients undergoing 167 primary TKAs performed for osteonecrosis between 2004 and 2014 at a single institution were reviewed. The mean age at index TKA was 61 years (14 to 93) and the mean body mass index (BMI) was 30 kg/m2 (18 to 51) The mean follow-up was six years (2 to 12). A total of 110 TKAs (66%) were performed for primary osteonecrosis and 57 TKAs (34%) for secondary osteonecrosis. Overall, 15 TKAs (9%) had tibial stems, while 12 TKAs (7%) had femoral stems. Posterior-stabilized designs were used in 147 TKAs (88%) of TKAs. Bivariate Cox regression analysis was conducted to identify risk factors for revision and reoperation.


The Bone & Joint Journal
Vol. 100-B, Issue 7 | Pages 925 - 929
1 Jul 2018
Abdel MP Tibbo ME Stuart MJ Trousdale RT Hanssen AD Pagnano MW

Aims

It has been suggested that mobile-bearing total knee arthroplasty (TKA) might lead to better outcomes by accommodating some femorotibial rotational mismatch, thereby reducing contact stresses and polyethylene wear. The aim of this study was to determine whether there is a difference between fixed- and mobile-bearing versions of a contemporary TKA with respect to durability, range of movement (ROM) and function, ten years postoperatively.

Patients and Methods

A total of 240 patients who were enrolled in this randomized controlled trial (RCT) underwent a primary cemented TKA with one of three tibial components (all-polyethylene fixed-bearing, modular metal-backed fixed-bearing and mobile-bearing). Patients were reviewed at a median follow-up of ten years (IQR 9.2 to 10.4).


The Bone & Joint Journal
Vol. 101-B, Issue 7_Supple_C | Pages 104 - 107
1 Jul 2019
Greenwell PH Shield WP Chapman DM Dalury DF

Aims

The aim of this study was to establish the results of isolated exchange of the tibial polyethylene insert in revision total knee arthroplasty (RTKA) in patients with well-fixed femoral or tibial components. We report on a series of RTKAs where only the polyethylene was replaced, and the patients were followed for a mean of 13.2 years (10.0 to 19.1).

Patients and Methods

Our study group consisted of 64 non-infected, grossly stable TKA patients revised over an eight-year period (1998 to 2006). The mean age of the patients at time of revision was 72.2 years (48 to 88). There were 36 females (56%) and 28 males (44%) in the cohort. All patients had received the same cemented, cruciate-retaining patella resurfaced primary TKA. All subsequently underwent an isolated polyethylene insert exchange. The mean time from the primary TKA to RTKA was 9.1 years (2.2 to 16.1).


The Bone & Joint Journal
Vol. 100-B, Issue 10 | Pages 1330 - 1335
1 Oct 2018
Ponzio DY Weitzler L deMeireles A Esposito CI Wright TM Padgett DE

Aims

The aim of this study was to evaluate the surface damage, the density of crosslinking, and oxidation in retrieved antioxidant-stabilized highly crosslinked polyethylene (A-XLPE) tibial inserts from total knee arthroplasty (TKA), and to compare the results with a matched cohort of standard remelted highly crosslinked polyethylene (XLPE) inserts.

Materials and Methods

A total of 19 A-XLPE tibial inserts were retrieved during revision TKA and matched to 18 retrieved XLPE inserts according to the demographics of the patients, with a mean length of implantation of 15 months (1 to 42). The percentage areas of PE damage on the articular surfaces and the modes of damage were measured. The density of crosslinking of the PE and oxidation were measured at loaded and unloaded regions on these surfaces.


The Bone & Joint Journal
Vol. 100-B, Issue 9 | Pages 1162 - 1167
1 Sep 2018
Metcalfe AJ Ahearn N Hassaballa MA Parsons N Ackroyd CE Murray JR Robinson JR Eldridge JD Porteous AJ

Aims

This study reports on the medium- to long-term implant survivorship and patient-reported outcomes for the Avon patellofemoral joint (PFJ) arthroplasty.

Patients and Methods

A total of 558 Avon PFJ arthroplasties in 431 patients, with minimum two-year follow-up, were identified from a prospective database. Patient-reported outcomes and implant survivorship were analyzed, with follow-up of up to 18 years.


The Bone & Joint Journal
Vol. 99-B, Issue 8 | Pages 996 - 1002
1 Aug 2017
Brown TS Van Citters DW Berry DJ Abdel MP

Advances in polyethylene (PE) in total hip arthroplasty have led to interest and increased use of highly crosslinked PE (HXLPE) in total knee arthroplasty (TKA). Biomechanical data suggest improved wear characteristics for HXLPE inserts over conventional PE in TKA. Short-term results from registry data and few clinical trials are promising. Our aim is to present a review of the history of HXLPEs, the use of HXLPE inserts in TKA, concerns regarding potential mechanical complications, and a thorough review of the available biomechanical and clinical data.

Cite this article: Bone Joint J 2017;99-B:996–1002.


The Bone & Joint Journal
Vol. 95-B, Issue 9 | Pages 1209 - 1216
1 Sep 2013
van der Voort P Pijls BG Nouta KA Valstar ER Jacobs WCH Nelissen RGHH

Mobile-bearing (MB) total knee replacement (TKR) was introduced to reduce the risk of aseptic loosening and wear of polyethylene inserts. However, no consistent clinical advantages of mobile- over fixed-bearing (FB) TKR have been found. In this study we evaluated whether mobile bearings have an advantage over fixed bearings with regard to revision rates and clinical outcome scores. Furthermore, we determined which modifying variables affected the outcome.

A systematic search of the literature was conducted to collect clinical trials comparing MB and FB in primary TKR. The primary outcomes were revision rates for any reason, aseptic loosening and wear. Secondary outcomes included range of movement, Knee Society score (KSS), Oxford knee score (OKS), Short-Form 12 (SF-12) score and radiological parameters. Meta-regression techniques were used to explore factors modifying the observed effect.

Our search yielded 1827 publications, of which 41 studies met our inclusion criteria, comprising over 6000 TKRs. Meta-analyses showed no clinically relevant differences in terms of revision rates, clinical outcome scores or patient-reported outcome measures between MB and FB TKRs. It appears that theoretical assumptions of superiority of MB over FB TKR are not borne out in clinical practice.

Cite this article: Bone Joint J 2013;95-B:1209–16.


The Bone & Joint Journal
Vol. 100-B, Issue 1_Supple_A | Pages 76 - 82
1 Jan 2018
Benjamin B Pietrzak JRT Tahmassebi J Haddad FS

Aims

The outcome of total knee arthroplasty (TKA) is not always satisfactory. The purpose of this study was to identify satisfaction and biomechanical features characterising the gait of patients who had undergone TKA with either an anatomical single radius design or a medial pivot design. We hypothesised that the latter would provide superior function.

Patients and Methods

This is a study of a subset of patients recruited into a prospective randomised study of a single radius design versus a medial pivot design, with a minimum follow-up of one year. Outcome measurements included clinical scores (Knee Society Score (KSS) and Oxford Knee Score (OKS)) and gait analysis using an instrumented treadmill.


The Bone & Joint Journal
Vol. 100-B, Issue 2 | Pages 152 - 160
1 Feb 2018
Subramanyam KN Khanchandani P Tulajaprasad PV Jaipuria J Mundargi AV

Aims

The aims of this study were to compare the efficacy and safety of intra-articular and intravenous (IV) tranexamic acid (TXA) in controlling perioperative blood loss in total knee arthroplasty (TKA) using a randomized, double-blinded equivalence trial.

Patients and Methods

A total of 182 patients aged between 45 and 75 years undergoing unilateral TKA at a tertiary centre were randomized to receive TXA, either 1.5 g intra-articularly after closure of the wound (n = 91) or two doses of 10 mg/kg IV (n = 91). The primary outcome measure was the reduction in the level of haemoglobin (Hb) in the blood on the fifth postoperative day. Secondary outcome measures were the total, visible, and hidden blood losses (TBL, VBL, HBL). We assumed equivalence of the primary outcome in both routes with a margin of ± 0.35gm/dl. Block randomization using computer-generated random numbers was used. The patients and the assessor of outcome were blinded.


The Bone & Joint Journal
Vol. 99-B, Issue 9 | Pages 1153 - 1156
1 Sep 2017
Harrison PL Harrison T Stockley I Smith TJ

Aims

Tantalum (Ta) trabecular metal components are increasingly used to reconstruct major bone defects in revision arthroplasty surgery. It is known that some metals such as silver have antibacterial properties. Recent reports have raised the question regarding whether Ta components are protective against infection in revision surgery. This laboratory study aimed to establish whether Ta has intrinsic antibacterial properties against planktonic bacteria, or the ability to inhibit biofilm formation.

Materials and Methods

Equal-sized pieces of Ta and titanium (Ti) acetabular components were sterilised and incubated with a low dose inoculum of either Staphylococcus (S.) aureus or S. epidermidis for 24 hours. After serial dilution, colony forming units (cfu) were quantified on Mueller-Hinton agar plates. In order to establish whether biofilms formed to a greater extent on one material than the other, these Ta and Ti pieces were then washed twice, sonicated and washed again to remove loosely adhered planktonic bacteria. They were then re-incubated for 24 hours prior to quantifying the number of cfu. All experiments were performed in triplicate.


The Bone & Joint Journal
Vol. 99-B, Issue 8 | Pages 1037 - 1046
1 Aug 2017
Scott CEH Turnbull GS MacDonald D Breusch SJ

Aims

Little is known about employment following total knee arthroplasty (TKA). This study aims to identify factors which predict return to work following TKA in patients of working age in the United Kingdom.

Patients & Methods

We prospectively assessed 289 patients (289 TKAs) aged ≤ 65 years who underwent TKA between 2010 and 2013. There were 148 women. The following were recorded pre-operatively: age, gender, body mass index, social deprivation, comorbidities, indication for surgery, work status and nature of employment, activity level as assessed by the University of California, Los Angeles (UCLA) activity score and Oxford Knee Score (OKS). The intention of patients to return to work or to retire was not assessed pre-operatively. At a mean of 3.4 years (2 to 4) post-operatively, the return to work status, OKS, the EuroQol-5 dimensions (EQ-5D) score, UCLA activity score and Work, Osteoarthritis and joint-Replacement (WORQ) score were obtained. Univariate and multivariate analyses were performed.


The Journal of Bone & Joint Surgery British Volume
Vol. 91-B, Issue 4 | Pages 463 - 468
1 Apr 2009
Fukunaga K Kobayashi A Minoda Y Iwaki H Hashimoto Y Takaoka K

The patellar clunk syndrome describes painful catching, grinding or jumping of the patella when the knee moves from a flexed to an extended position after total knee replacement (TKR). The posterior stabilised TKR had been noted to have a higher incidence of this problem. Mobile-bearing posteriorly stabilised TKRs have been introduced to improve patellar tracking and related problems by a mechanism of self-alignment. We evaluated the patellar clunk syndrome in 113 knees in 93 patients with such a TKR at a mean follow-up of 2.3 years (2.0 to 3.2). The syndrome was identified in 15 knees (13.3%).

Logistic regression analysis showed that the absolute value of the post-operative angle of patellar tilt was significantly associated with the occurrence of patellar clunk (p = 0.025). Patellar tracking should be carefully checked during surgery.


The Bone & Joint Journal
Vol. 98-B, Issue 8 | Pages 1050 - 1055
1 Aug 2016
Karachalios T Varitimidis S Bargiotas K Hantes M Roidis N Malizos KN

Aims

The Advance Medial-Pivot total knee arthroplasty (TKA) was designed to reflect contemporary data regarding the kinematics of the knee. We wished to examine the long-term results obtained with this prosthesis by extending a previous evaluation.

Patients and Methods

We retrospectively evaluated prospectively collected data from 225 consecutive patients (41 men and 184 women; mean age at surgery 71 years, 52 to 84) who underwent 284 TKAs with a mean follow-up of 13.4 years (11 to 15). Implant failure, complication rate, clinical (both subjective and objective) and radiological outcome were assessed. Pre- and post-operative clinical and radiographic data were available at regular intervals for all patients. A total of ten patients (4.4%; ten TKAs) were lost to follow-up.


The Journal of Bone & Joint Surgery British Volume
Vol. 89-B, Issue 7 | Pages 904 - 910
1 Jul 2007
Kim Y Kim D Kim J

We conducted a randomised prospective study to evaluate the clinical and radiological results of a mobile- and fixed-bearing total knee replacement of similar design in 174 patients who had bilateral simultaneous knee replacement. The mean follow-up was for 5.6 years (5.2 to 6.1).

The total knee score, pain score, functional score and range of movement were not statistically different (p > 0.05) between the two groups. Osteolysis was not seen in any knee in either group. Two knees (1%) in the mobile-bearing group required revision because of infection; none in the fixed-bearing group needed revision. Excellent results can be achieved with both mobile- and fixed-bearing prostheses of similar design at mid-term follow-up. We could demonstrate no significant clinical advantage for a mobile bearing.


The Journal of Bone & Joint Surgery British Volume
Vol. 87-B, Issue 7 | Pages 940 - 945
1 Jul 2005
Pandit H Ward T Hollinghurst D Beard DJ Gill HS Thomas NP Murray DW

Abnormal sagittal kinematics after total knee replacement (TKR) can adversely affect functional outcome. Two important determinants of knee kinematics are component geometry and the presence or absence of a posterior-stabilising mechanism (cam-post). We investigated the influence of these variables by comparing the kinematics of a TKR with a polyradial femur with a single radius design, both with and without a cam-post mechanism.

We assessed 55 patients, subdivided into four groups, who had undergone a TKR one year earlier by using an established fluoroscopy protocol in order to examine their kinematics in vivo. The kinematic profile was obtained by measuring the patellar tendon angle through the functional knee flexion range (0° to 90°) and the results compared with 14 normal knees. All designs of TKR had abnormal sagittal kinematics compared with the normal knee. There was a significant (p < 0.05) difference between those of the two TKRs near to full extension. The presence of the cam-post mechanism did not influence the kinematics for either TKR design. These differences suggest that surface geometry is a stronger determinant of kinematics than the presence or absence of a cam-post mechanism for these two designs. This may be because the cam-post mechanism is ineffective.


The Bone & Joint Journal
Vol. 98-B, Issue 4 | Pages 490 - 497
1 Apr 2016
Maempel JF Wickramasinghe NR Clement ND Brenkel IJ Walmsley PJ

Aims

The pre-operative level of haemoglobin is the strongest predictor of the peri-operative requirement for blood transfusion after total knee arthroplasty (TKA). There are, however, no studies reporting a value that could be considered to be appropriate pre-operatively.

This study aimed to identify threshold pre-operative levels of haemoglobin that would predict the requirement for blood transfusion in patients who undergo TKA.

Patients and Methods

Analysis of receiver operator characteristic (ROC) curves of 2284 consecutive patients undergoing unilateral TKA was used to determine gender specific thresholds predicting peri-operative transfusion with the highest combined sensitivity and specificity (area under ROC curve 0.79 for males; 0.78 for females).


The Bone & Joint Journal
Vol. 98-B, Issue 2 | Pages 249 - 259
1 Feb 2016
Sabharwal S Carter AW Rashid A Darzi A Reilly P Gupte CM

Aims

The aims of this study were to estimate the cost of surgical treatment of fractures of the proximal humerus using a micro-costing methodology, contrast this cost with the national reimbursement tariff and establish the major determinants of cost.

Methods

A detailed inpatient treatment pathway was constructed using semi-structured interviews with 32 members of hospital staff. Its content validity was established through a Delphi panel evaluation. Costs were calculated using time-driven activity-based costing (TDABC) and sensitivity analysis was performed to evaluate the determinants of cost


The Bone & Joint Journal
Vol. 96-B, Issue 5 | Pages 609 - 618
1 May 2014
Gøthesen Ø Espehaug B Havelin LI Petursson G Hallan G Strøm E Dyrhovden G Furnes O

We performed a randomised controlled trial comparing computer-assisted surgery (CAS) with conventional surgery (CONV) in total knee replacement (TKR). Between 2009 and 2011 a total of 192 patients with a mean age of 68 years (55 to 85) with osteoarthritis or arthritic disease of the knee were recruited from four Norwegian hospitals. At three months follow-up, functional results were marginally better for the CAS group. Mean differences (MD) in favour of CAS were found for the Knee Society function score (MD: 5.9, 95% confidence interval (CI) 0.3 to 11.4, p = 0.039), the Knee Injury and Osteoarthritis Outcome Score (KOOS) subscales for ‘pain’ (MD: 7.7, 95% CI 1.7 to 13.6, p = 0.012), ‘sports’ (MD: 13.5, 95% CI 5.6 to 21.4, p = 0.001) and ‘quality of life’ (MD: 7.2, 95% CI 0.1 to 14.3, p = 0.046). At one-year follow-up, differences favouring CAS were found for KOOS ‘sports’ (MD: 11.0, 95% CI 3.0 to 19.0, p = 0.007) and KOOS ‘symptoms’ (MD: 6.7, 95% CI 0.5 to 13.0, p = 0.035). The use of CAS resulted in fewer outliers in frontal alignment (> 3° malalignment), both for the entire TKR (37.9% vs 17.9%, p = 0.042) and for the tibial component separately (28.4% vs 6.3%, p = 0.002). Tibial slope was better achieved with CAS (58.9% vs 26.3%, p < 0.001). Operation time was 20 minutes longer with CAS. In conclusion, functional results were, statistically, marginally in favour of CAS. Also, CAS was more predictable than CONV for mechanical alignment and positioning of the prosthesis. However, the long-term outcomes must be further investigated.

Cite this article: Bone Joint J 2014; 96-B:609–18.


The Bone & Joint Journal
Vol. 97-B, Issue 10_Supple_A | Pages 9 - 15
1 Oct 2015
Parratte S Ollivier M Lunebourg A Abdel MP Argenson J

Partial knee arthroplasty (PKA), either medial or lateral unicompartmental knee artroplasty (UKA) or patellofemoral arthroplasty (PFA) are a good option in suitable patients and have the advantages of reduced operative trauma, preservation of both cruciate ligaments and bone stock, and restoration of normal kinematics within the knee joint. However, questions remain concerning long-term survival. The goal of this review article was to present the long-term results of medial and lateral UKA, PFA and combined compartmental arthroplasty for multicompartmental disease. Medium- and long-term studies suggest reasonable outcomes at ten years with survival greater than 95% in UKA performed for medial osteoarthritis or osteonecrosis, and similarly for lateral UKA, particularly when fixed-bearing implants are used. Disappointing long-term outcomes have been observed with the first generation of patellofemoral implants, as well as early Bi-Uni (ie, combined medial and lateral UKA) or Bicompartmental (combined UKA and PFA) implants due to design and fixation issues. Promising short- and med-term results with the newer generations of PFAs and bicompartmental arthroplasties will require long-term confirmation.

Cite this article: Bone Joint J 2015;97-B(10 Suppl A):9–15.


The Bone & Joint Journal
Vol. 95-B, Issue 10 | Pages 1339 - 1347
1 Oct 2013
Scott CEH Eaton MJ Nutton RW Wade FA Pankaj P Evans SL

As many as 25% to 40% of unicompartmental knee replacement (UKR) revisions are performed for pain, a possible cause of which is proximal tibial strain. The aim of this study was to examine the effect of UKR implant design and material on cortical and cancellous proximal tibial strain in a synthetic bone model. Composite Sawbone tibiae were implanted with cemented UKR components of different designs, either all-polyethylene or metal-backed. The tibiae were subsequently loaded in 500 N increments to 2500 N, unloading between increments. Cortical surface strain was measured using a digital image correlation technique. Cancellous damage was measured using acoustic emission, an engineering technique that detects sonic waves (‘hits’) produced when damage occurs in material.

Anteromedial cortical surface strain showed significant differences between implants at 1500 N and 2500 N in the proximal 10 mm only (p < 0.001), with relative strain shielding in metal-backed implants. Acoustic emission showed significant differences in cancellous bone damage between implants at all loads (p = 0.001). All-polyethylene implants displayed 16.6 times the total number of cumulative acoustic emission hits as controls. All-polyethylene implants also displayed more hits than controls at all loads (p < 0.001), more than metal-backed implants at loads ≥ 1500 N (p < 0.001), and greater acoustic emission activity on unloading than controls (p = 0.01), reflecting a lack of implant stiffness. All-polyethylene implants were associated with a significant increase in damage at the microscopic level compared with metal-backed implants, even at low loads. All-polyethylene implants should be used with caution in patients who are likely to impose large loads across their knee joint.

Cite this article: Bone Joint J 2013;95-B:1339–47.


The Journal of Bone & Joint Surgery British Volume
Vol. 92-B, Issue 6 | Pages 794 - 798
1 Jun 2010
Minoda Y Ikebuchi M Kobayashi A Iwaki H Inori F Nakamura H

Bone mineral density (BMD) around the femoral component has been reported to decrease after total knee replacement (TKR) because of stress shielding. Our aim was to determine whether a cemented mobile-bearing component reduced the post-operative loss of BMD. In our study 28 knees receiving a cemented fixed-bearing TKR were matched with 28 receiving a cemented mobile-bearing TKR. They underwent dual-energy x-ray absorptiometry, pre-operatively and at three weeks and at three, six, 12, 18 and 24 months post-operatively. The patients were not taking medication to improve the BMD.

The pre-operative differences in the BMD of the femoral neck, wrist, lumbar spine and knee in the two groups were not significant. The BMD of the femur decreased postoperatively in the fixed-bearing group, but not the mobile-bearing group. The difference in the post-operative change in the BMD in the two groups was statistically significant (p < 0.05) at 18 and 24 months.

Our findings show that a cemented mobile-bearing TKR has a favourable effect on the BMD of the distal femur after TKR in the short term. Further study is required to determine the long-term effects.


The Bone & Joint Journal
Vol. 96-B, Issue 11_Supple_A | Pages 115 - 117
1 Nov 2014
Mullaji A Shetty GM

Stems may improve fixation and stability of components during revision total knee replacement. However, the choice between cemented and cementless stems is not a clear one. Cemented stems offer several advantages in terms of versatility, mechanical stability, surgical technique and clinical outcome over their cementless counterpart.

Cite this article: Bone Joint J 2014;96-B(11 Suppl A):115–7.


The Journal of Bone & Joint Surgery British Volume
Vol. 94-B, Issue 8 | Pages 1009 - 1015
1 Aug 2012
Scott CEH Biant LC

Stems improve the mechanical stability of tibial components in total knee replacement (TKR), but come at a cost of stress shielding along their length. Their advantages include resistance to shear, reduced tibial lift-off and increased stability by reducing micromotion. Longer stems may have disadvantages including stress shielding along the length of the stem with associated reduction in bone density and a theoretical risk of subsidence and loosening, peri-prosthetic fracture and end-of-stem pain. These features make long stems unattractive in the primary TKR setting, but often desirable in revision surgery with bone loss and instability. In the revision scenario, stems are beneficial in order to convey structural stability to the construct and protect the reconstruction of bony defects. Cemented and uncemented long stemmed implants have different roles depending on the nature of the bone loss involved.

This review discusses the biomechanics of the design of tibial components and stems to inform the selection of the component and the technique of implantation.


The Bone & Joint Journal
Vol. 97-B, Issue 4 | Pages 503 - 509
1 Apr 2015
Maempel JF Clement ND Brenkel IJ Walmsley PJ

This study demonstrates a significant correlation between the American Knee Society (AKS) Clinical Rating System and the Oxford Knee Score (OKS) and provides a validated prediction tool to estimate score conversion.

A total of 1022 patients were prospectively clinically assessed five years after TKR and completed AKS assessments and an OKS questionnaire. Multivariate regression analysis demonstrated significant correlations between OKS and the AKS knee and function scores but a stronger correlation (r = 0.68, p < 0.001) when using the sum of the AKS knee and function scores. Addition of body mass index and age (other statistically significant predictors of OKS) to the algorithm did not significantly increase the predictive value.

The simple regression model was used to predict the OKS in a group of 236 patients who were clinically assessed nine to ten years after TKR using the AKS system. The predicted OKS was compared with actual OKS in the second group. Intra-class correlation demonstrated excellent reliability (r = 0.81, 95% confidence intervals 0.75 to 0.85) for the combined knee and function score when used to predict OKS.

Our findings will facilitate comparison of outcome data from studies and registries using either the OKS or the AKS scores and may also be of value for those undertaking meta-analyses and systematic reviews.

Cite this article: Bone Joint J 2015;97-B:503–9.


The Bone & Joint Journal
Vol. 96-B, Issue 10 | Pages 1319 - 1324
1 Oct 2014
Oh JS Youm YS Cho SD Choi SW Cho YJ

Previous studies support the important role of vascular endothelial growth factor (VEGF) and syndecan-4 in the pathogenesis of osteoarthritis (OA). Both VEGF and syndecan-4 are expressed by chondrocytes and both are involved in the regulation of matrix metalloproteinase-3, resulting in the activation of aggrecanase II (ADAMTS-5), which is essential in the pathogenesis of OA. However, the relationship between VEGF and syndecan-4 has not been established. As a pilot study, we assayed the expression of VEGF and syndecan-4 in cartilage samples and cultured chondrocytes from osteoarthritic knee joints and analysed the relationship between these two factors.

Specimens were collected from 21 female patients (29 knees) who underwent total knee replacement due to severe medial OA of the knee (Kellgren–Lawrence grade 4). Articular cartilage samples, obtained from bone and cartilage excised during surgery, were analysed and used for chondrocyte culture. We found that the levels of expression of VEGF and syndecan-4 mRNA did not differ significantly between medial femoral cartilage with severe degenerative changes and lateral femoral cartilage that appeared grossly normal (p = 0.443 and 0.622, respectively). Likewise, the levels of expression of VEGF and syndecan-4 mRNA were similar in cultured chondrocytes from medial and lateral femoral cartilage. The levels of expression of VEGF and syndecan-4 mRNAs were significantly and positively correlated in cartilage explant (r = 0.601, p = 0.003) but not in cultured chondrocytes. These results suggest that there is a close relationship between VEGF and syndecan-4 in the cartilage of patients with OA. Further studies are needed to determine the exact pathway by which these two factors interact in the pathogenesis of OA.

Cite this article: Bone Joint J 2014;96-B:1319–24.


The Journal of Bone & Joint Surgery British Volume
Vol. 93-B, Issue 12 | Pages 1653 - 1659
1 Dec 2011
Bordei P

Platelet-derived growth factor (PDGF) is known to stimulate osteoblast or osteoprogenitor cell activity. We investigated the effect of locally applied PDGF from poly-d,l-lactide (PDLLA)-coated implants on fracture healing in a rat model. A closed fracture of the right tibia of four-month-old Sprague-Dawley rats (n = 40) was stabilised with implants coated with a biodegradable PDLLA versus implants coated with PDLLA and PDGF. Radiographs were taken throughout the study, and a marker of DNA activity, bromodeoxyuridine (BrdU), was injected before the rats were killed at three, seven and ten days. The radiographs showed consolidation of the callus in the PDGF-treated group compared with the control group at all three time points. In the PDGF-treated group, immunohistochemical staining of BrdU showed that the distribution of proliferating cells in all cellular events was higher after ten days compared with that at three and seven days.

These results indicate that local application of PDGF from biodegradable PDLLA-coated implants significantly accelerates fracture healing in experimental animals. Further development may help fracture healing in the clinical situation.


The Journal of Bone & Joint Surgery British Volume
Vol. 93-B, Issue 10 | Pages 1355 - 1361
1 Oct 2011
Bollars P Luyckx J Innocenti B Labey L Victor J Bellemans J

High-flexion total knee replacement (TKR) designs have been introduced to improve flexion after TKR. Although the early results of such designs were promising, recent literature has raised concerns about the incidence of early loosening of the femoral component. We compared the minimum force required to cause femoral component loosening for six high-flexion and six conventional TKR designs in a laboratory experiment.

Each TKR design was implanted in a femoral bone model and placed in a loading frame in 135° of flexion. Loosening of the femoral component was induced by moving the tibial component at a constant rate of displacement while maintaining the same angle of flexion. A stereophotogrammetric system registered the relative movement between the femoral component and the underlying bone until loosening occurred.

Compared with high-flexion designs, conventional TKR designs required a significantly higher force before loosening occurred (p < 0.001). High-flexion designs with closed box geometry required significantly higher loosening forces than high-flexion designs with open box geometry (p = 0.0478). The presence of pegs further contributed to the fixation strength of components.

We conclude that high-flexion designs have a greater risk for femoral component loosening than conventional TKR designs. We believe this is attributable to the absence of femoral load sharing between the prosthetic component and the condylar bone during flexion.


The Journal of Bone & Joint Surgery British Volume
Vol. 92-B, Issue 9 | Pages 1253 - 1258
1 Sep 2010
Scott CEH Howie CR MacDonald D Biant LC

Up to 20% of patients are not satisfied with the outcome following total knee replacement (TKR). This study investigated the pre- and post-operative predictors of dissatisfaction in a large cohort of patients undergoing TKR. We assessed 1217 consecutive patients between 2006 and 2008 both before operation and six months after, using the Short-form (SF)-12 health questionnaire and the Oxford Knee Score. Detailed information concerning comorbidity was also gathered. Satisfaction was measured at one year when 18.6% (226 of 1217) of patients were unsure or dissatisfied with their replacement and 81.4% (911 of 1217) were satisfied or very satisfied. Multivariate regression analysis was performed to identify independent predictors of dissatisfaction. Significant (p < 0.001) predictors at one year included the pre-operative SF-12 mental component score, depression and pain in other joints, the six-month SF-12 score and poorer improvement in the pain element of the Oxford Knee Score.

Patient expectations were highly correlated with satisfaction. Satisfaction following TKR is multifactorial. Managing the expectations and mental health of the patients may reduce dissatisfaction. However, the most significant predictor of dissatisfaction is a painful total knee replacement.


The Bone & Joint Journal
Vol. 95-B, Issue 12 | Pages 1632 - 1639
1 Dec 2013
Clement ND MacDonald D Simpson AHRW Burnett R

This study assessed the effect of concomitant back pain on the Oxford knee score (OKS), Short-Form (SF)-12 and patient satisfaction after total knee replacement (TKR). It involved a prospectively compiled database of demographics and outcome scores for 2392 patients undergoing primary TKR, of whom 829 patients (35%) reported back pain. Compared with those patients without back pain, those with back pain were more likely to be female (odds ratio (OR) 1.5 (95% confidence interval (CI) 1.3 to 1.8)), have a greater level of comorbidity, a worse pre-operative OKS (2.3 points (95% CI 1.7 to 3.0)) and worse SF-12 physical (2.0 points (95% CI 1.4 to 2.6)) and mental (3.3 points (95% CI 2.3 to 4.3)) components.

One year post-operatively, those with back pain had significantly worse outcome scores than those without with a mean difference in the OKS of 5 points (95% CI 3.8 to 5.4), in the SF-12 physical component of 6 points (95% CI 5.4 to 7.1) and in the mental component of 4 points (95% CI 3.1 to 4.9). Patients with back pain were less likely to be satisfied (OR 0.62, 95% CI 0.5 to 0.78).

After adjusting for confounding variables, concomitant back pain was an independent predictor of a worse post-operative OKS, and of dissatisfaction. Clinicians should be aware that patients suffering concomitant back pain pre-operatively are at an increased risk of being dissatisfied post-operatively.

Cite this article: Bone Joint J 2013;95-B:1632–9.


The Bone & Joint Journal
Vol. 95-B, Issue 6 | Pages 788 - 792
1 Jun 2013
Chen JY Lo NN Jiang L Chong HC Tay DKJ Chin PL Chia S Yeo SJ

We prospectively followed 171 patients who underwent bilateral unicompartmental knee replacement (UKR) over a period of two years. Of these, 124 (72.5%) underwent a simultaneous bilateral procedure and 47 (27.5%) underwent a staged procedure. The mean cumulative operating time and length of hospital stay were both shorter in the simultaneous group, by 22.5 minutes (p < 0.001) and three days (p < 0.001), respectively. The mean reduction in haemoglobin level post-operatively was greater by 0.15 g/dl in the simultaneous group (p = 0.023), but this did not translate into a significant increase in the number of patients requiring blood transfusion (p = 1.000). The mean hospital cost was lower by $8892 in the simultaneous group (p < 0.001). There was no significant difference in the rate of complications between the groups, and at two-year follow-up there was no difference in the outcomes between the two groups.

We conclude that simultaneous bilateral UKR can be recommended as an appropriate treatment for patients with bilateral medial compartment osteoarthritis of the knee.

Cite this article: Bone Joint J 2013;95-B:788–92.


The Bone & Joint Journal
Vol. 95-B, Issue 9 | Pages 1269 - 1274
1 Sep 2013
Uppal HS Peterson BE Misfeldt ML Della Rocca GJ Volgas DA Murtha YM Stannard JP Choma TJ Crist BD

We hypothesised that cells obtained via a Reamer–Irrigator–Aspirator (RIA) system retain substantial osteogenic potential and are at least equivalent to graft harvested from the iliac crest. Graft was harvested using the RIA in 25 patients (mean age 37.6 years (18 to 68)) and from the iliac crest in 21 patients (mean age 44.6 years (24 to 78)), after which ≥ 1 g of bony particulate graft material was processed from each. Initial cell viability was assessed using Trypan blue exclusion, and initial fluorescence-activated cell sorting (FACS) analysis for cell lineage was performed. After culturing the cells, repeat FACS analysis for cell lineage was performed and enzyme-linked immunosorbent assay (ELISA) for osteocalcin, and Alizarin red staining to determine osteogenic potential. Cells obtained via RIA or from the iliac crest were viable and matured into mesenchymal stem cells, as shown by staining for the specific mesenchymal antigens CD90 and CD105. For samples from both RIA and the iliac crest there was a statistically significant increase in bone production (both p < 0.001), as demonstrated by osteocalcin production after induction.

Medullary autograft cells harvested using RIA are viable and osteogenic. Cell viability and osteogenic potential were similar between bone grafts obtained from both the RIA system and the iliac crest.

Cite this article: Bone Joint J 2013;95-B:1269–74.


The Bone & Joint Journal
Vol. 95-B, Issue 3 | Pages 295 - 300
1 Mar 2013
Cawley DT Kelly N McGarry JP Shannon FJ

The optimum cementing technique for the tibial component in cemented primary total knee replacement (TKR) remains controversial. The technique of cementing, the volume of cement and the penetration are largely dependent on the operator, and hence large variations can occur. Clinical, experimental and computational studies have been performed, with conflicting results. Early implant migration is an indication of loosening. Aseptic loosening is the most common cause of failure in primary TKR and is the product of several factors. Sufficient penetration of cement has been shown to increase implant stability.

This review discusses the relevant literature regarding all aspects of the cementing of the tibial component at primary TKR.

Cite this article: Bone Joint J 2013;95-B:295–300.


The Journal of Bone & Joint Surgery British Volume
Vol. 89-B, Issue 4 | Pages 471 - 476
1 Apr 2007
Kim Y Kim J Yoon S

Bilateral sequential total knee replacement was carried out under one anaesthetic in 100 patients. One knee was replaced using a CT-free computer-assisted navigation system and the other conventionally without navigation. The two methods were compared for accuracy of orientation and alignment of the components. There were 85 women and 15 men with a mean age of 67.6 years (54 to 83). Radiological and CT imaging was carried out to determine the alignment of the components. The mean follow-up was 2.3 years (2 to 3).

The operating and tourniquet times were significantly longer in the navigation group (p < 0.001). There were no significant pre- or post-operative differences between the knee scores of the two groups (p = 0.288 and p = 0.429, respectively). The results of imaging and the number of outliers for all radiological parameters were not statistically different (p = 0.109 to p = 0.920).

In this series computer-assisted navigated total knee replacement did not result in more accurate orientation and alignment of the components than that achieved by conventional total knee replacement.


The Journal of Bone & Joint Surgery British Volume
Vol. 88-B, Issue 8 | Pages 1016 - 1021
1 Aug 2006
Delport HP Banks SA De Schepper J Bellemans J

Mobile-bearing posterior-stabilised knee replacements have been developed as an alternative to the standard fixed- and mobile-bearing designs. However, little is known about the in vivo kinematics of this new group of implants. We investigated 31 patients who had undergone a total knee replacement with a similar prosthetic design but with three different options: fixed-bearing posterior cruciate ligament-retaining, fixed-bearing posterior-stabilised and mobile-bearing posterior-stabilised. To do this we used a three-dimensional to two-dimensional model registration technique. Both the fixed- and mobile-bearing posterior-stabilised configurations used the same femoral component. We found that fixed-bearing posterior stabilised and mobile-bearing posterior-stabilised knee replacements demonstrated similar kinematic patterns, with consistent femoral roll-back during flexion. Mobile-bearing posterior-stabilised knee replacements demonstrated greater and more natural internal rotation of the tibia during flexion than fixed-bearing posterior-stabilised designs. Such rotation occurred at the interface between the insert and tibial tray for mobile-bearing posterior-stabilised designs. However, for fixed-bearing posterior-stabilised designs, rotation occurred at the proximal surface of the bearing. Posterior cruciate ligament-retaining knee replacements demonstrated paradoxical sliding forward of the femur.

We conclude that mobile-bearing posterior-stabilised knee replacements reproduce internal rotation of the tibia more closely during flexion than fixed-bearing posterior-stabilised designs. Furthermore, mobile-bearing posterior-stabilised knee replacements demonstrate a unidirectional movement which occurs at the upper and lower sides of the mobile insert. The femur moves in an anteroposterior direction on the upper surface of the insert, whereas the movement at the lower surface is pure rotation. Such unidirectional movement may lead to less wear when compared with the multidirectional movement seen in fixed-bearing posterior-stabilised knee replacements, and should be associated with more evenly applied cam-post stresses.


The Journal of Bone & Joint Surgery British Volume
Vol. 94-B, Issue 11 | Pages 1457 - 1461
1 Nov 2012
Krishnan SP Dawood A Richards R Henckel J Hart AJ

Improvements in the surgical technique of total knee replacement (TKR) are continually being sought. There has recently been interest in three-dimensional (3D) pre-operative planning using magnetic resonance imaging (MRI) and CT. The 3D images are increasingly used for the production of patient-specific models, surgical guides and custom-made implants for TKR.

The users of patient-specific instrumentation (PSI) claim that they allow the optimum balance of technology and conventional surgery by reducing the complexity of conventional alignment and sizing tools. In this way the advantages of accuracy and precision claimed by computer navigation techniques are achieved without the disadvantages of additional intra-operative inventory, new skills or surgical time.

This review describes the terminology used in this area and debates the advantages and disadvantages of PSI.


The Journal of Bone & Joint Surgery British Volume
Vol. 87-B, Issue 4 | Pages 583 - 587
1 Apr 2005
Szöke G Lee S Simpson AHRW Prescott J

Little is known about the increase in length of tendons in postnatal life or of their response to limb lengthening procedures. A study was carried out in ten young and nine adult rabbits in which the tibia was lengthened by 20% at two rates 0.8 mm/day and 1.6 mm/day.

The tendon of the flexor digitorum longus (FDL) muscle showed a significant increase in length in response to lengthening of the tibia. The young rabbits exhibited a significantly higher increase in length in the FDL tendon compared with the adults. There was no difference in the amount of lengthening of the FDL tendon at the different rates. Of the increase in length which occurred, 77% was in the proximal half of the tendon.

This investigation demonstrated that tendons have the ability to lengthen during limb distraction. This occurred to a greater extent in the young who showed a higher proliferative response, suggesting that there may be less need for formal tendon lengthening in young children.


The Journal of Bone & Joint Surgery British Volume
Vol. 88-B, Issue 10 | Pages 1321 - 1326
1 Oct 2006
Amin AK Clayton RAE Patton JT Gaston M Cook RE Brenkel IJ

The results of 41 consecutive total knee replacements performed on morbidly obese patients with a body mass index > 40 kg/m2, were compared with a matched group of 41 similar procedures carried out in non-obese patients (body mass index < 30 kg/m2). The groups were matched for age, gender, diagnosis, type of prosthesis, laterality and pre-operative Knee Society Score. We prospectively followed up the patients for a mean of 38.5 months (6 to 66). No patients were lost to follow-up. At less than four years after operation, the results were worse in the morbidly obese group compared with the non-obese, as demonstrated by inferior Knee Society Scores (mean knee score 85.7 and 90.5 respectively, p = 0.08; mean function score 75.6 and 83.4, p = 0.01), a higher incidence of radiolucent lines on post-operative radiographs (29% and 7%, respectively, p = 0.02), a higher rate of complications (32% and 0%, respectively, p = 0.001) and inferior survivorship using revision and pain as end-points (72.3% and 97.6%, respectively, p = 0.02).

Patients with a body mass index > 40 kg/m2 should be advised to lose weight prior to total knee replacement and to maintain weight reduction. They should also be counselled regarding the inferior results which may occur if they do not lose weight before surgery.


The Bone & Joint Journal
Vol. 95-B, Issue 3 | Pages 360 - 366
1 Mar 2013
Clement ND MacDonald D Burnett R

We assessed the effect of mental disability on the outcome of total knee replacement (TKR) and investigated whether mental health improves post-operatively. Outcome data were prospectively recorded over a three-year period for 962 patients undergoing primary TKR for osteoarthritis. Pre-operative and one year Short-Form (SF)-12 scores and Oxford knee scores (OKS) were obtained. The mental component of the SF-12 was stratified into four groups according to level of mental disability (none ≥ 50, mild 40 to 49, moderate 30 to 39, severe < 30). Patients with any degree of mental disability had a significantly greater subjective physical disability according to the SF-12 (p = 0.06) and OKS (p < 0.001). The improvement in the disease-specific score (OKS) was not affected by a patient’s mental health (p = 0.33). In contrast, patients with mental disability had less of an improvement in their global physical health (SF-12) (p < 0.001). However, patients with any degree of mental disability had a significant improvement in their mental health post-operatively (p < 0.001).

Despite a similar improvement in their disease-specific scores and improvement in their mental health, patients with mental disability were significantly more likely to be dissatisfied with their TKR at one year (p = 0.001). Patients with poor mental health do benefit from improvements in their mental health and knee function after TKR, but also have a higher rate of dissatisfaction.

Cite this article: Bone Joint J 2013;95-B:360–6.


The Journal of Bone & Joint Surgery British Volume
Vol. 94-B, Issue 10 | Pages 1351 - 1355
1 Oct 2012
Collins RA Walmsley PJ Amin AK Brenkel IJ Clayton RAE

A total of 445 consecutive primary total knee replacements (TKRs) were followed up prospectively at six and 18 months and three, six and nine years. Patients were divided into two groups: non-obese (body mass index (BMI) < 30 kg/m2) and obese (BMI ≥ 30 kg/m2). The obese group was subdivided into mildly obese (BMI 30 to 35 kg/m2) and highly obese (BMI ≥ 35 kg/m2) in order to determine the effects of increasing obesity on outcome. The clinical data analysed included the Knee Society score, peri-operative complications and implant survival. There was no difference in the overall complication rates or implant survival between the two groups.

Obesity appears to have a small but significant adverse effect on clinical outcome, with highly obese patients showing lower function scores than non-obese patients. However, significant improvements in outcome are sustained in all groups nine years after TKR. Given the substantial, sustainable relief of symptoms after TKR and the low peri-operative complication and revision rates in these two groups, we have found no reason to limit access to TKR in obese patients.


The Bone & Joint Journal
Vol. 95-B, Issue 1 | Pages 52 - 58
1 Jan 2013
Clement ND Jenkins PJ DM Nie YX Patton JT Breusch SJ Howie CR Biant LC

We assessed the effect of social deprivation upon the Oxford knee score (OKS), the Short-Form 12 (SF-12) and patient satisfaction after total knee replacement (TKR). An analysis of 966 patients undergoing primary TKR for symptomatic osteoarthritis (OA) was performed. Social deprivation was assessed using the Scottish Index of Multiple Deprivation. Those patients that were most deprived underwent surgery at an earlier age (p = 0.018), were more likely to be female (p = 0.046), to endure more comorbidities (p = 0.04) and to suffer worse pain and function according to the OKS (p < 0.001). In addition, deprivation was also associated with poor mental health (p = 0.002), which was assessed using the mental component (MCS) of the SF-12 score. Multivariable analysis was used to identify independent predictors of outcome at one year. Pre-operative OKS, SF-12 MCS, back pain, and four or more comorbidities were independent predictors of improvement in the OKS (all p < 0.001). Pre-operative OKS and improvement in the OKS were independent predictors of dissatisfaction (p = 0.003 and p < 0.001, respectively). Although improvement in the OKS and dissatisfaction after TKR were not significantly associated with social deprivation per se, factors more prevalent within the most deprived groups significantly diminished their improvement in OKS and increased their rate of dissatisfaction following TKR.

Cite this article: Bone Joint J 2013;95-B:52–8.


The Journal of Bone & Joint Surgery British Volume
Vol. 94-B, Issue 2 | Pages 200 - 204
1 Feb 2012
Clement ND Jenkins PJ Brenkel IJ Walmsley P

We report the general mortality rate after total knee replacement and identify independent predictors of survival. We studied 2428 patients: there were 1127 men (46%) and 1301 (54%) women with a mean age of 69.3 years (28 to 94). Patients were allocated a predicted life expectancy based on their age and gender.

There were 223 deaths during the study period. This represented an overall survivorship of 99% (95% confidence interval (CI) 98 to 99) at one year, 90% (95% CI 89 to 92) at five years, and 84% (95% CI 82 to 86) at ten years. There was no difference in survival by gender. A greater mortality rate was associated with increasing age (p < 0.001), American Society of Anesthesiologists (ASA) grade (p < 0.001), smoking (p < 0.001), body mass index (BMI) <  20 kg/m2 (p < 0.001) and rheumatoid arthritis (p < 0.001). Multivariate modelling confirmed the independent effect of age, ASA grade, BMI, and rheumatoid disease on mortality. Based on the predicted average mortality, 114 patients were predicted to have died, whereas 217 actually died. This resulted in an overall excess standardised mortality ratio of 1.90. Patient mortality after TKR is predicted by their demographics: these could be used to assign an individual mortality risk after surgery.


The Journal of Bone & Joint Surgery British Volume
Vol. 94-B, Issue 5 | Pages 642 - 647
1 May 2012
Mullaji A Lingaraju AP Shetty GM

We retrospectively reviewed the records of 1150 computer-assisted total knee replacements and analysed the clinical and radiological outcomes of 45 knees that had arthritis with a pre-operative recurvatum deformity. The mean pre-operative hyperextension deformity of 11° (6° to 15°), as measured by navigation at the start of the operation, improved to a mean flexion deformity of 3.1° (0° to 7°) post-operatively. A total of 41 knees (91%) were managed using inserts ≤ 12.5 mm thick, and none had mediolateral laxity > 2 mm from a mechanical axis of 0° at the end of the surgery. At a mean follow-up of 26.4 months (13 to 48) there was significant improvement in the mean Knee Society, Oxford knee and Western Ontario and McMaster Universities Osteoarthritis Index scores compared with the pre-operative values. The mean knee flexion improved from 105° (80° to 125°) pre-operatively to 131° (120° to 145°), and none of the limbs had recurrent recurvatum.

These early results show that total knee replacement using computer navigation and an algorithmic approach for arthritic knees with a recurvatum deformity can give excellent radiological and functional outcomes without recurrent deformity.


The Journal of Bone & Joint Surgery British Volume
Vol. 94-B, Issue 4 | Pages 510 - 516
1 Apr 2012
Hickey BA Kempshall PJ Metcalfe AJ Forster MC

As part of the national initiative to reduce waiting times for joint replacement surgery in Wales, the Cardiff and Vale NHS Trust referred 224 patients to the NHS Treatment Centre in Weston-Super-Mare for total knee replacement (TKR). A total of 258 Kinemax TKRs were performed between November 2004 and August 2006. Of these, a total of 199 patients (232 TKRs, 90%) have been followed up for five years. This cohort was compared with 258 consecutive TKRs in 250 patients, performed at Cardiff and Vale Orthopaedic Centre (CAVOC) over a similar time period. The five year cumulative survival rate was 80.6% (95% confidence interval (CI) 74.0 to 86.0) in the Weston-Super-Mare cohort and 95.0% (95% CI 90.2 to 98.2) in the CAVOC cohort with revision for any reason as the endpoint. The relative risk for revision at Weston-Super-Mare compared with CAVOC was 3.88 (p < 0.001). For implants surviving five years, the mean Oxford knee scores (OKS) and mean EuroQol (EQ-5D) scores were similar (OKS: Weston-Super-Mare 29 (2 to 47) vs CAVOC 29.8 (3 to 48), p = 0.61; EQ-5D: Weston-Super-Mare 0.53 (-0.38 to 1.00) vs CAVOC 0.55 (-0.32 to 1.00), p = 0.79). Patients with revised TKRs had significantly lower Oxford knee and EQ-5D scores (p < 0.001).

The results show a higher revision rate for patients operated at Weston-Super-Mare Treatment Centre, with a reduction in functional outcome and quality of life after revision. This further confirms that patients moved from one area to another for joint replacement surgery fare poorly.


The Journal of Bone & Joint Surgery British Volume
Vol. 87-B, Issue 5 | Pages 656 - 663
1 May 2005
Toms AD McClelland D Chua L de Waal Malefijt M Verdonschot N Jones RS Kuiper J

Clinical experience of impaction bone grafting for revision knee arthroplasty is limited, with initial stability of the tibial tray emerging as a major concern. The length of the stem and its diameter have been altered to improve stability. Our aim was to investigate the effect of the type of stem, support of the rim and graft impaction on early stability of the tray.

We developed a system for impaction grafting of trays which we used with morsellised bone in artificial tibiae. Trays with short, long thick or long thin stems were implanted, with or without support of the rim. They were cyclically loaded while measuring relative movement.

Long-stemmed trays migrated 4.5 times less than short-stemmed trays, regardless of diameter. Those with support migrated 2.8 times less than those without. The migration of short-stemmed trays correlated inversely with the density of the impacted groups. That of impaction-grafted tibial trays was in the range reported for uncemented primary trays. Movements of short-stemmed trays without cortical support were largest and sensitive to the degree of compaction of the graft. If support of the rim was sufficient or a long stem was used, impacted morsellised bone graft achieved adequate initial stability.


The Journal of Bone & Joint Surgery British Volume
Vol. 92-B, Issue 12 | Pages 1710 - 1716
1 Dec 2010
Chia W Pan R Tseng F Chen Y Feng C Lee H Chang D Sytwu H

The patellofemoral joint is an important source of symptoms in osteoarthritis of the knee. We have used a newly designed surgical model of patellar strengthening to induce osteoarthritis in BALB/c mice and to establish markers by investigating the relationship between osteoarthritis and synovial levels of matrix metalloproteinases (MMPs). Osteoarthritis was induced by using this microsurgical technique under direct vision without involving the cavity of the knee. Degeneration of cartilage was assessed by the Mankin score and synovial tissue was used to determine the mRNA expression levels of MMPs. Irrigation fluid from the knee was used to measure the concentrations of MMP-3 and MMP-9. Analysis of cartilage degeneration was correlated with the levels of expression of MMP.

After operation the patellofemoral joint showed evidence of mild osteoarthritis at eight weeks and further degenerative changes by 12 weeks. The level of synovial MMP-9 mRNA correlated with the Mankin score at eight weeks, but not at 12 weeks. The levels of MMP-2, MMP-3 and MMP-14 mRNA correlated with the Mankin score at 12 weeks. An increase in MMP-3 was observed from four weeks up to 16 weeks. MMP-9 was notably increased at eight weeks, but the concentration at 16 weeks had decreased to the level observed at four weeks.

Our observations suggest that MMP-2, MMP-3 and MMP-14 could be used as markers of the progression of osteoarthritic change.


The Journal of Bone & Joint Surgery British Volume
Vol. 92-B, Issue 7 | Pages 994 - 998
1 Jul 2010
Jenkins PJ Teoh K Simpson PM Dave J Simpson AHWR Breusch S

Antibiotic prophylaxis is routinely administered during joint replacement surgery and may predispose patients to Clostridium difficile-associated disease (CDAD). The primary aim of this study was to determine the incidence of this following joint replacement, using a cefuroxime-based regimen. Patients developing CDAD were compared with a control group of patients without CDAD. The incidence of the former was 1.7 per 1000 primary joint replacements. Those patients prescribed additional antibiotics had a higher incidence of CDAD (p = 0.047), but there was no difference between the two groups in relation to the use of gastroprotective agents (p = 0.703). A trial of a new prophylaxis regimen would require 43 198 patients in each arm to show a reduction of one case per 1000 procedures. Cefuroxime-based antibiotic prophylaxis is safe in patients undergoing primary elective joint replacement.


The Journal of Bone & Joint Surgery British Volume
Vol. 93-B, Issue 3 | Pages 357 - 363
1 Mar 2011
Gillespie RJ Levine A Fitzgerald SJ Kolaczko J DeMaio M Marcus RE Cooperman DR

Recently, gender-specific designs of total knee replacement have been developed to accommodate anatomical differences between males and females. We examined a group of male and female distal femora matched for age and height, to determine if there was a difference in the aspect ratio (mediolateral distance versus anteroposterior distance) and the height of the anterior flange between the genders. The Hamann-Todd Collection provided 1207 skeletally mature cadaver femora. The femoral length, the anteroposterior height, height of the lateral and medial flanges and the mediolateral width were measured in all the specimens. The mechanical axis of the femur, the cut articular width and the aspect ratio were assessed. Statistical analysis of the effect of gender upon the aspect ratio and the lateral and medial flanges was undertaken, controlling for age, height and race.

The mean aspect ratio of male femora was 1.21 (sd 0.07) and of female femora it was 1.16 (sd 0.06) (p < 0.001). There was no significant difference between male and female specimens in the mean size of the lateral flange (6.57 mm (sd 2.57) and 7.02 mm (sd 2.36), respectively; p = 0.099) or of the medial flange (3.03 mm (sd 2.47) and 3.56 mm (sd 2.32), respectively; p = 0.67). Future work in the design of knee prostheses should take into account the overall variability of the anatomy of the distal femur.


The Journal of Bone & Joint Surgery British Volume
Vol. 92-B, Issue 7 | Pages 1033 - 1040
1 Jul 2010
Nishino T Chang F Ishii T Yanai T Mishima H Ochiai N

We have previously shown that joint distraction and movement with a hinged external fixation device for 12 weeks was useful for repairing a large articular cartilage defect in a rabbit model. We have now investigated the results after six months and one year. The device was applied to 16 rabbits who underwent resection of the articular cartilage and subchondral bone from the entire tibial plateau. In group A (nine rabbits) the device was applied for six months. In group B (seven rabbits) it was in place for six months, after which it was removed and the animals were allowed to move freely for an additional six months. The cartilage remained sound in all rabbits. The areas of type II collagen-positive staining and repaired soft tissue were larger in group B than in group A. These findings provide evidence of long-term persistence of repaired cartilage with this technique and that weight-bearing has a positive effect on the quality of the cartilage.


The Journal of Bone & Joint Surgery British Volume
Vol. 93-B, Issue 3 | Pages 370 - 377
1 Mar 2011
Chaudhury S Dicko C Burgess M Vollrath F Carr AJ

We have used Fourier transform infrared spectroscopy (FTIR) to characterise the chemical and structural composition of the tendons of the rotator cuff and to identify structural differences among anatomically distinct tears. Such information may help to identify biomarkers of tears and to provide insight into the rates of healing of different sizes of tear. The infrared spectra of 81 partial, small, medium, large and massive tears were measured using FTIR and compared with 11 uninjured control tendons. All the spectra were classified using standard techniques of multivariate analysis.

FTIR readily differentiates between normal and torn tendons, and different sizes of tear. We identified the key discriminating molecules and spectra altered in torn tendons to be carbohydrates/phospholipids (1030 cm−1 to 1200 cm−1), collagen (1300 cm−1 to 1700 cm−1 and 3000 cm−1 to 3350 cm−1) and lipids (2800 cm−1 to 3000 cm−1).

Our study has shown that FTIR spectroscopy can identify tears of the rotator cuff of varying size based upon distinguishable chemical and structural features. The onset of a tear is mainly associated with altered structural arrangements of collagen, with changes in lipids and carbohydrates. The approach described is rapid and has the potential to be used peri-operatively to determine the quality of the tendon and the extent of the disease, thus guiding surgical repair.


The Journal of Bone & Joint Surgery British Volume
Vol. 92-B, Issue 11 | Pages 1501 - 1508
1 Nov 2010
Donell ST Darrah C Nolan JF Wimhurst J Toms A Barker THW Case CP Tucker JK

Metal-on-metal total hip replacement has been targeted at younger patients with anticipated long-term survival, but the effect of the production of metal ions is a concern because of their possible toxicity to cells. We have reviewed the results of the use of the Ultima hybrid metal-on-metal total hip replacement, with a cemented polished tapered femoral component with a 28 mm diameter and a cobalt-chrome (CoCr) modular head, articulating with a 28 mm CoCr acetabular bearing surface secured in a titanium alloy uncemented shell.

Between 1997 and 2004, 545 patients with 652 affected hips underwent replacement using this system. Up to 31 January 2008, 90 (13.8%) hips in 82 patients had been revised. Pain was the sole reason for revision in 44 hips (48.9%) of which 35 had normal plain radiographs. Peri-prosthetic fractures occurred in 17 hips (18.9%) with early dislocation in three (3.3%) and late dislocation in 16 (17.8%). Infection was found in nine hips (10.0%).

At operation, a range of changes was noted including cavities containing cloudy fluid under pressure, necrotic soft tissues with avulsed tendons and denuded osteonecrotic upper femora. Corrosion was frequently observed on the retrieved cemented part of the femoral component. Typically, the peri-operative findings confirmed those found on pre-operative metal artefact reduction sequence MRI and histological examination showed severe necrosis.

Metal artefact reduction sequence MRI proved to be useful when investigating these patients with pain in the absence of adverse plain radiological features.


The Journal of Bone & Joint Surgery British Volume
Vol. 90-B, Issue 9 | Pages 1239 - 1243
1 Sep 2008
Zhang N Li ZR Wei H Liu Z Hernigou P

Severe acute respiratory syndrome (SARS) is a newly described infectious disease caused by the SARS coronavirus which attacks the immune system and pulmonary epithelium. It is treated with regular high doses of corticosteroids. Our aim was to determine the relationship between the dosage of steroids and the number and distribution of osteonecrotic lesions in patients treated with steroids during the SARS epidemic in Beijing, China in 2003.

We identified 114 patients for inclusion in the study. Of these, 43 with osteonecrosis received a significantly higher cumulative and peak methylprednisolone-equivalent dose than 71 patients with no osteonecrosis identified by MRI. We confirmed that the number of osteonecrotic lesions was directly related to the dosage of steroids and that a very high dose, a peak dose of more than 200 mg or a cumulative methylprednisolone-equivalent dose of more than 4000 mg, is a significant risk factor for multifocal osteonecrosis with both epiphyseal and diaphyseal lesions. Patients with diaphyseal osteonecrosis received a significantly higher cumulative methylprednisolone-equivalent dose than those with epiphyseal osteonecrosis. Multifocal osteonecrosis should be suspected if a patient is diagnosed with osteonecrosis in the shaft of a long bone.


The Journal of Bone & Joint Surgery British Volume
Vol. 90-B, Issue 11 | Pages 1435 - 1440
1 Nov 2008
Smith IDM Elton R Ballantyne JA Brenkel IJ

In Scotland, the number of primary total knee replacements performed annually has been increasing steadily. The price of the implant is fixed but the length of hospital stay is variable.

We prospectively investigated all patients who underwent primary unilateral total knee replacement in the Scottish region of Fife, between December 1994 and February 2007 and assessed their recorded pre-operative details. The data were analysed using univariate and multiple linear regression statistical analysis.

Data on the length of stay were available from a total of 2106 unilateral total knee replacements. The median length of hospital stay was eight days. The significant pre-operative risk factors for an increased length of stay were the year of admission, details of the consultant looking after the patient, the stair score, the walking-aid score and age.

Awareness of the pre-operative factors which increase the length of hospital stay may provide the opportunity to influence them favourably and to reduce the time in hospital and the associated costs of unilateral total knee replacement.


The Journal of Bone & Joint Surgery British Volume
Vol. 91-B, Issue 3 | Pages 409 - 416
1 Mar 2009
Anders JO Mollenhauer J Beberhold A Kinne RW Venbrocks RA

The gelatin-based haemostyptic compound Spongostan was tested as a three-dimensional (3D) chondrocyte matrix in an in vitro model for autologous chondrocyte transplantation using cells harvested from bovine knees. In a control experiment of monolayer cultures, the proliferation or de-differentiation of bovine chondrocytes was either not or only marginally influenced by the presence of Spongostan (0.3 mg/ml).

In monolayers and 3-D Minusheet culture chambers, the cartilage-specific differentiation markers aggrecan and type-II collagen were ubiquitously present in a cell-associated fashion and in the pericellular matrix. The Minusheet cultures usually showed a markedly higher mRNA expression than monolayer cultures irrespective of whether Spongostan had been present or not during culture. Although the de-differentiation marker type-I collagen was also present, the ratio of type-I to type-II collagen or aggrecan to type-I collagen remained higher in Minusheet 3-D cultures than in monolayer cultures irrespective of whether Spongostan had been included in or excluded from the monolayer cultures. The concentration of GAG in Minusheet cultures reached its maximum after 14 days with a mean of 0.83 ± 0.8 μg/106 cells; mean ±, sem, but remained considerably lower than in monolayer cultures with/without Spongostan.

Our results suggest that Spongostan is in principle suitable as a 3-D chondrocyte matrix, as demonstrated in Minusheet chambers, in particular for a culture period of 14 days. Clinically, differentiating effects on chondrocytes, simple handling and optimal formability may render Spongostan an attractive 3-D scaffold for autologous chondrocyte transplantation.


The Journal of Bone & Joint Surgery British Volume
Vol. 91-B, Issue 2 | Pages 271 - 277
1 Feb 2009
Toms AD Barker RL McClelland D Chua L Spencer-Jones R Kuiper J

The treatment of bony defects of the tibia at the time of revision total knee replacement is controversial. The place of compacted morsellised bone graft is becoming established, particularly in contained defects. It has previously been shown that the initial stability of impaction-grafted trays in the contained defects is equivalent to that of an uncemented primary knee replacement. However, there is little biomechanical evidence on which to base a decision in the treatment of uncontained defects. We undertook a laboratory-based biomechanical study comparing three methods of graft containment in segmental medial tibial defects and compared them with the use of a modular metal augment to bypass the defect.

Using resin models of the proximal tibia with medial defects representing either 46% or 65% of the medial cortical rim, repair of the defect was accomplished using mesh, cement or a novel bag technique, after which impaction bone grafting was used to fill the contained defects and a tibial component was cemented in place. As a control, a cemented tibial component with modular metal augments was used in identical defects. All specimens were submitted to cyclical mechanical loading, during which cyclical and permanent tray displacement were determined.

The results showed satisfactory stability with all the techniques except the bone bag method. Using metal augments gave the highest initial stability, but obviously lacked any potential for bone restoration.


The Journal of Bone & Joint Surgery British Volume
Vol. 90-B, Issue 7 | Pages 973 - 979
1 Jul 2008
Savadkoohi DG Sadeghipour P Attarian H Sardari S Eslamifar A Shokrgozar MA

Curettage and packing with polymethylmethacrylate cement is a routine treatment for giant-cell tumour (GCT) of bone. We performed an in vitro evaluation of the cytotoxic effect of a combination of cement and methotrexate, doxorubicin and cisplatin on primary cell cultures of stromal GCT cells obtained from five patients. Cement cylinders containing four different concentrations of each drug were prepared, and the effect of the eluted drugs was examined at three different time intervals.

We found that the cytotoxic effect of eluted drugs depended on their concentration and the time interval, with even the lowest dose of each drug demonstrating an acceptable rate of cytotoxicity. Even in low doses, cytotoxic drugs mixed with polymethylmethacrylate cement could therefore be considered as effective local adjuvant treatment for GCTs.


The Journal of Bone & Joint Surgery British Volume
Vol. 91-B, Issue 3 | Pages 417 - 424
1 Mar 2009
Millar NL Wei AQ Molloy TJ Bonar F Murrell GAC

The role of inflammatory cells and their products in tendinopathy is not completely understood. Pro-inflammatory cytokines are upregulated after oxidative and other forms of stress. Based on observations that increased cytokine expression has been demonstrated in cyclically-loaded tendon cells we hypothesised that because of their role in oxidative stress and apoptosis, pro-inflammatory cytokines may be present in rodent and human models of tendinopathy. A rat supraspinatus tendinopathy model produced by running overuse was investigated at the genetic level by custom micro-arrays. Additionally, samples of torn supraspinatus tendon and matched intact subscapularis tendon were collected from patients undergoing arthroscopic shoulder surgery for rotator-cuff tears and control samples of subscapularis tendon from ten patients with normal rotator cuffs undergoing arthroscopic stabilisation of the shoulder were also obtained. These were all evaluated using semiquantitative reverse transcription polymerase chain-reaction and immunohistochemistry.

We identified significant upregulation of pro-inflammatory cytokines and apoptotic genes in the rodent model (p = 0.005). We further confirmed significantly increased levels of cytokine and apoptotic genes in human supraspinatus and subscapularis tendon harvested from patients with rotator cuff tears (p = 0.0008).

These findings suggest that pro-inflammatory cytokines may play a role in tendinopathy and may provide a target for preventing tendinopathies.


The Journal of Bone & Joint Surgery British Volume
Vol. 90-B, Issue 2 | Pages 166 - 171
1 Feb 2008
Lundblad H Kreicbergs A Jansson K

We suggest that different mechanisms underlie joint pain at rest and on movement in osteoarthritis and that separate assessment of these two features with a visual analogue scale (VAS) offers better information about the likely effect of a total knee replacement (TKR) on pain. The risk of persistent pain after TKR may relate to the degree of central sensitisation before surgery, which might be assessed by determining the pain threshold to an electrical stimulus created by a special tool, the Pain Matcher. Assessments were performed in 69 patients scheduled for TKR. At 18 months after operation, separate assessment of pain at rest and with movement was again carried out using a VAS in order to enable comparison of pre- and post-operative measurements. A less favourable outcome in terms of pain relief was observed for patients with a high pre-operative VAS score for pain at rest and a low pain threshold, both features which may reflect a central sensitisation mechanism.


The Journal of Bone & Joint Surgery British Volume
Vol. 90-B, Issue 6 | Pages 745 - 750
1 Jun 2008
Millar NL Murrell GAC

We identified ten patients who underwent arthroscopic revision of anterior shoulder stabilisation between 1999 and 2005. Their results were compared with 15 patients, matched for age and gender, who had a primary arthroscopic stabilisation during the same period.

At a mean follow-up of 37 and 36 months, respectively, the scores for pain and shoulder function improved significantly between the pre-operative and follow-up visits in both groups (p = 0.002), with no significant difference between them (p = 0.4). The UCLA and Rowe shoulder scores improved significantly (p = 0.004 and p = 0.002, respectively), with no statistically significant differences between groups (p = 0.6). Kaplan-Meier analysis for time to recurrent instability showed no differences between the groups (p = 0.2).

These results suggest that arthroscopic revision anterior shoulder stabilisation is as reliable as primary arthroscopic stabilisation for patients who have had previous open surgery for recurrent anterior instability.


The Journal of Bone & Joint Surgery British Volume
Vol. 87-B, Issue 7 | Pages 965 - 968
1 Jul 2005
Stannard JP Singhania AK Lopez-Ben RR Anderson ER Farris RC Volgas DA McGwin GR Alonso JE

We report the incidence and location of deep-vein thrombosis in 312 patients who had sustained high-energy, skeletal trauma. They were investigated using magnetic resonance venography and Duplex ultrasound.

Despite thromboprophylaxis, 36 (11.5%) developed venous thromboembolic disease with an incidence of 10% in those with non-pelvic trauma and 12.2% in the group with pelvic trauma. Of patients who developed deep-vein thrombosis, 13 of 27 in the pelvic group (48%) and only one of nine in the non-pelvic group (11%) had a definite pelvic deep-vein thrombosis. When compared with magnetic resonance venography, ultrasound had a false-negative rate of 77% in diagnosing pelvic deep-vein thrombosis. Its value in the pelvis was limited, although it was more accurate than magnetic resonance venography in diagnosing clots in the lower limbs. Additional screening may be needed to detect pelvic deep-vein thrombosis in patients with pelvic or acetabular fractures.


The Journal of Bone & Joint Surgery British Volume
Vol. 88-B, Issue 12 | Pages 1660 - 1665
1 Dec 2006
Surendran S Kim SH Jee BK Ahn SH Gopinathan P Han CW

We stably transfected early passage chondrocytes with an anti-apoptotic Bcl-2 gene in vitro using a retrovirus vector. Samples of articular cartilage were obtained from 11 patients with a mean age of 69 years (61 to 75) who were undergoing total knee replacement for osteoarthritis. The Bcl-2-gene-transfected chondrocytes were compared with non-transfected and lac-Z-gene-transfected chondrocytes, both of which were used as controls. All three groups of cultured chondrocytes were incubated with nitric oxide (NO) for ten days. Using the Trypan Blue exclusion assay, an enzyme-linked immunosorbent assay and flow cytometric analysis, we found that the number of apoptotic chondrocytes was significantly higher in the non-transfected and lac-Z-transfected groups than in the Bcl-2-transfected group (p < 0.05). The Bcl-2-transfected chondrocytes were protected from NO-induced impairment of proteoglycan synthesis.

We conclude that NO-induced chondrocyte death involves a mechanism which appears to be subject to regulation by an anti-apoptotic Bcl-2 gene. Therefore, Bcl-2 gene therapy may prove to be of therapeutic value in protecting human articular chondrocytes.


The Journal of Bone & Joint Surgery British Volume
Vol. 89-B, Issue 10 | Pages 1317 - 1323
1 Oct 2007
Kim Y Yoon S Kim J

We compared the results of 146 patients who received an anatomic modular knee fixed-bearing total knee replacement (TKR) in one knee and a low contact stress rotating platform mobile-bearing TKR in the other. There were 138 women and eight men with a mean age of 69.8 years (42 to 80). The mean follow-up was 13.2 years (11.0 to 14.5). The patients were assessed clinically and radiologically using the rating systems of the Hospital for Special Surgery and the Knee Society at three months, six months, one year, and annually thereafter.

The assessment scores of both rating systems pre-operatively and at the final review did not show any statistically significant differences between the two designs of implant. In the anatomic modular knee group, one knee was revised because of aseptic loosening of the tibial component and one because of infection. In addition, three knees were revised because of wear of the polyethylene tibial bearing. In the low contact stress group, two knees were revised because of instability requiring exchange of the polyethylene insert and one because of infection.

The radiological analysis found no statistical difference in the incidence of radiolucent lines at the final review (Student’s t-test, p = 0.08), most of which occurred at tibial zone 1. The Kaplan-Meier survivorship for aseptic loosening of the anatomic modular knee and the low contact stress implants at 14.5 years was 99% and 100%, respectively, with a 95% confidence interval of 94% to 100% for both designs.

We found no evidence of the superiority of one design over the other at long-term follow-up.


The Journal of Bone & Joint Surgery British Volume
Vol. 88-B, Issue 9 | Pages 1252 - 1256
1 Sep 2006
Mayr E Krismer M Ertl M Kessler O Thaler M Nogler M

A complete cement mantle is important for the longevity of a total hip replacement. In the minimally-invasive direct anterior approach used at the Innsbruck University hospital, the femoral component has to be inserted into the femoral canal by an angulated movement. In a cadaver study, the quality and the extent of the cement mantle surrounding 13 Exeter femoral components implanted straight through a standard anterolateral transgluteal approach were compared with those of 13 similar femoral components implanted in an angulated fashion through a direct anterior approach. A third-generation cementing technique was used. The inner and outer contours of the cement mantles was traced from CT scans and the thickness and cross-sectional area determined.

In no case was the cement mantle incomplete. The total mean thickness of the cement mantle was 3.62 mm (95% confidence interval 3.59 to 3.65). The mean thickness in the group using the minimally-invasive approach was 0.16 mm less than that in the anterolateral group. The distribution of the thickness was similar in the two groups. The mean thickness was less on the anteromedial and anterolateral aspect than on the posterior aspect of the femur.

There is no evidence that the angulated introduction of Exeter femoral components in the direct anterior approach in cadavers compromises the quality, extent or thickness of the cement mantle.


The Journal of Bone & Joint Surgery British Volume
Vol. 88-B, Issue 1 | Pages 129 - 133
1 Jan 2006
Lee SY Miwa M Sakai Y Kuroda R Niikura T Kurosaka M

We have investigated whether cells derived from haemarthrosis caused by injury to the anterior cruciate ligament could differentiate into the osteoblast lineage in vitro. Haemarthroses associated with anterior cruciate ligament injuries were aspirated and cultured. After treatment with β-glycerophosphate, ascorbic acid and dexamethasone or 1,25 (OH)2D3, a significant increase in the activity of alkaline phosphatase was observed. Matrix mineralisation was demonstrated after 28 days and mRNA levels in osteoblast-related genes were enhanced.

Our results suggest that the haemarthrosis induced by injury to the anterior cruciate ligament contains osteoprogenitor cells and is a potential alternative source for cell-based treatment in such injury.


The Journal of Bone & Joint Surgery British Volume
Vol. 89-B, Issue 9 | Pages 1165 - 1171
1 Sep 2007
Gohil S Annear PO Breidahl W

Animal studies have shown that implanted anterior cruciate ligament (ACL) grafts initially undergo a process of revascularisation prior to remodelling, ultimately increasing mechanical strength. We investigated whether minimal debridement of the intercondylar notch and the residual stump of the ruptured ACL leads to earlier revascularisation in ACL reconstruction in humans. We undertook a randomised controlled clinical trial in which 49 patients underwent ACL reconstruction using autologous four-strand hamstring tendon grafts. Randomised by the use of sealed envelopes, 25 patients had a conventional clearance of the intercondylar notch and 24 had a minimal debridement method. Three patients were excluded from the study. All patients underwent MR scanning postoperatively at 2, 6 and 12 months, together with clinical assessment using a KT-1000 arthrometer and International Knee Documentation Committee (IKDC) evaluation. All observations were made by investigators blinded to the surgical technique. Signal intensity was measured in 4 mm diameter regions of interest along the ACL graft and the mid-substance of the posterior cruciate ligament.

Our results indicate that minimal debridement leads to earlier revascularisation within the mid-substance of the ACL graft at two months (paired t-test, p = 0.002). There was a significant reduction of mid-substance signal six months after the minimal debridement technique (paired t-test, p = 0.00007). No statistically significant differences were found in tunnel placement, incidence of Cyclops lesions, blood loss, IKDC scores, range of movement or Lachman test between the two groups.


The Journal of Bone & Joint Surgery British Volume
Vol. 88-B, Issue 11 | Pages 1441 - 1447
1 Nov 2006
Cui W Won Y Baek M Kim K Cho J

The appearance of the ‘grand-piano sign’ on the anterior resected surface of the femur has been considered to be a marker for correct femoral rotational alignment during total knee replacement. Our study was undertaken to assess quantitatively the morphological patterns on the resected surface after anterior femoral resection with various angles of external rotation, using a computer-simulation technique. A total of 50 right distal femora with varus osteoarthritis in 50 Korean patients were scanned using computerised tomography. Computer image software was used to simulate the anterior femoral cut, which was applied at an external rotation of 0°, 3° and 6° relative to the posterior condylar axis, and parallel to the surgical and clinical epicondylar axes in each case. The morphological patterns on the resected surface were quantified and classified as the ‘grand-piano sign’, ‘the boot sign’ and the ‘butterfly sign’. The surgeon can use the analogy of these quantified sign patterns to ensure that a correct rotational alignment has been obtained intra-operatively.


The Journal of Bone & Joint Surgery British Volume
Vol. 88-B, Issue 1 | Pages 49 - 53
1 Jan 2006
Tsumara N Yoshiya S Chin T Shiba R Kohso K Doita M

We undertook a prospective, randomised study in order to evaluate the efficacy of clamping the drains after intra-articular injection of saline with 1:500 000 adrenaline compared with post-operative blood salvage in reducing blood loss in 212 total knee arthroplasties. The mean post-operative drained blood volume after drain clamping was 352.1 ml compared to 662.3 ml after blood salvage (p < 0.0001). Allogenic blood transfusion was needed in one patient in the drain group and for three in the blood salvage group. Drain clamping with intra-articular injection of saline with adrenaline is more effective than post-operative autologous blood transfusion in reducing blood loss during total knee arthroplasty.


The Journal of Bone & Joint Surgery British Volume
Vol. 90-B, Issue 1 | Pages 114 - 121
1 Jan 2008
Pendegrass CJ Gordon D Middleton CA Sun SNM Blunn GW

Conventional amputation prostheses rely on the attachment of the socket to the stump, which may lead to soft-tissue complications. Intraosseous transcutaneous amputation prostheses (ITAPs) allow direct loading of the skeleton, but their success is limited by infection resulting from breaching of the skin at the interface with the implant. Keratinocytes provide the skin’s primary barrier function, while hemidesmosomes mediate their attachment to natural ITAP analogues. Keratinocytes must attach directly to the surface of the implant. We have assessed the proliferation, morphology and attachment of keratinocytes to four titaniumalloy surfaces in order to determine the optimal topography in vitro. We used immunolocalisation of adhesion complex components, scanning electron microscopy and transmission electron microscopy to assess cell parameters.

We have shown that the proliferation, morphology and attachment of keratinocytes are affected by the surface topography of the biomaterials used to support their growth. Smoother surfaces improved adhesion. We postulate that a smooth topography at the point of epithelium-ITAP contact could increase attachment in vivo, producing an effective barrier of infection.