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The Bone & Joint Journal
Vol. 104-B, Issue 10 | Pages 1118 - 1125
4 Oct 2022
Suda Y Hiranaka T Kamenaga T Koide M Fujishiro T Okamoto K Matsumoto T

Aims. A fracture of the medial tibial plateau is a serious complication of Oxford mobile-bearing unicompartmental knee arthroplasty (OUKA). The risk of these fractures is reportedly lower when using components with a longer keel-cortex distance (KCDs). The aim of this study was to examine how slight varus placement of the tibial component might affect the KCDs, and the rate of tibial plateau fracture, in a clinical setting. Methods. This retrospective study included 255 patients who underwent 305 OUKAs with cementless tibial components. There were 52 males and 203 females. Their mean age was 73.1 years (47 to 91), and the mean follow-up was 1.9 years (1.0 to 2.0). In 217 knees in 187 patients in the conventional group, tibial cuts were made orthogonally to the tibial axis. The varus group included 88 knees in 68 patients, and tibial cuts were made slightly varus using a new osteotomy guide. Anterior and posterior KCDs and the origins of fracture lines were assessed using 3D CT scans one week postoperatively. The KCDs and rate of fracture were compared between the two groups. Results. Medial tibial fractures occurred after surgery in 15 patients (15 OUKAs) in the conventional group, but only one patient (one OUKA) had a tibial fracture after surgery in the varus group. This difference was significant (6.9% vs 1.1%; p = 0.029). The mean posterior KCD was significantly shorter in the conventional group (5.0 mm (SD 1.7)) than in the varus group (6.1 mm (SD 2.1); p = 0.002). Conclusion. In OUKA, the distance between the keel and posterior tibial cortex was longer in our patients with slight varus alignment of the tibial component, which seems to decrease the risk of postoperative tibial fracture. Cite this article: Bone Joint J 2022;104-B(10):1118–1125


The Bone & Joint Journal
Vol. 106-B, Issue 1 | Pages 28 - 37
1 Jan 2024
Gupta S Sadczuk D Riddoch FI Oliver WM Davidson E White TO Keating JF Scott CEH

Aims. This study aims to determine the rate of and risk factors for total knee arthroplasty (TKA) after operative management of tibial plateau fractures (TPFs) in older adults. Methods. This is a retrospective cohort study of 182 displaced TPFs in 180 patients aged ≥ 60 years, over a 12-year period with a minimum follow-up of one year. The mean age was 70.7 years (SD 7.7; 60 to 89), and 139/180 patients (77.2%) were female. Radiological assessment consisted of fracture classification; pre-existing knee osteoarthritis (OA); reduction quality; loss of reduction; and post-traumatic OA. Fracture depression was measured on CT, and the volume of defect estimated as half an oblate spheroid. Operative management, complications, reoperations, and mortality were recorded. Results. Nearly half of the fractures were Schatzker II AO B3.1 fractures (n = 85; 47%). Radiological knee OA was present at fracture in 59/182 TPFs (32.6%). Primary management was fixation in 174 (95.6%) and acute TKA in eight (4.4%). A total of 13 patients underwent late TKA (7.5%), most often within two years. By five years, 21/182 12% (95% confidence interval (CI) 6.0 to 16.7) had required TKA. Larger volume defects of greater depth on CT (median 15.9 mm vs 9.4 mm; p < 0.001) were significantly associated with TKA requirement. CT-measured joint depression of > 12.8 mm was associated with TKA requirement (area under the curve (AUC) 0.766; p = 0.001). Severe joint depression of > 15.5 mm (hazard ratio (HR) 6.15 (95% CI 2.60 to 14.55); p < 0.001) and pre-existing knee OA (HR 2.70 (95% CI 1.14 to 6.37); p = 0.024) were independently associated with TKA requirement. Where patients with severe joint depression of > 15.5 mm were managed with fixation, 11/25 ultimately required TKA. Conclusion. Overall, 12% of patients aged ≥ 60 years underwent TKA within five years of TPF. Severe joint depression and pre-existing knee arthritis were independent risk factors for both post-traumatic OA and TKA. These features should be investigated as potential indications for acute TKA in older adults with TPFs. Cite this article: Bone Joint J 2024;106-B(1):28–37


The Bone & Joint Journal
Vol. 102-B, Issue 7 | Pages 861 - 867
1 Jul 2020
Hiranaka T Yoshikawa R Yoshida K Michishita K Nishimura T Nitta S Takashiba K Murray D

Aims. Cementless unicompartmental knee arthroplasty (UKA) has advantages over cemented UKA, including improved fixation, but has a higher risk of tibial plateau fracture, particularly in Japanese patients. The aim of this multicentre study was to determine when cementless tibial components could safely be used in Japanese patients based on the size and shape of the tibia. Methods. The study involved 212 cementless Oxford UKAs which were undertaken in 174 patients in six hospitals. The medial eminence line (MEL), which is a line parallel to the tibial axis passing through the tip of medial intercondylar eminence, was drawn on preoperative radiographs. Knees were classified as having a very overhanging medial tibial condyle if this line passed medial to the medial tibial cortex. They were also classified as very small if a size A/AA tibial component was used. Results. The overall rate of fracture was 8% (17 out of 212 knees). The rate was higher in knees with very overhanging condyles (Odds ratio (OR) 13; p < 0.001) and with very small components (OR 7; p < 0.001). The OR was 21 (p < 0.001) in those with both very overhanging condyles and very small components. In all, 69% of knees (147) had neither very overhanging nor very small components, and the fracture rate in these patients was 1.4% (2 out of 147 knees). Males had a significantly reduced risk of fracture (OR 0.13; p = 0.002), probably because no males required very small components and females were more likely to have very overhanging condyles (OR 3; p = 0.013). 31% of knees (66) were in males and in these the rate of fracture was 1.5% (1 out of 66 knees). Conclusion. The rate of tibial plateau fracture in Japanese patients undergoing cementless UKA is high. We recommend that cemented tibial fixation should be used in Japanese patients who require very small components or have very overhanging condyles, as identified from preoperative radiographs. In the remaining 69% of knees cementless fixation can be used. This approach should result in a low rate of fracture. Cite this article: Bone Joint J 2020;102-B(7):861–867


The Bone & Joint Journal
Vol. 105-B, Issue 10 | Pages 1078 - 1085
1 Oct 2023
Cance N Batailler C Shatrov J Canetti R Servien E Lustig S

Aims. Tibial tubercle osteotomy (TTO) facilitates surgical exposure and protects the extensor mechanism during revision total knee arthroplasty (rTKA). The purpose of this study was to determine the rates of bony union, complications, and reoperations following TTO during rTKA, to assess the functional outcomes of rTKA with TTO at two years’ minimum follow-up, and to identify the risk factors of failure. Methods. Between January 2010 and September 2020, 695 rTKAs were performed and data were entered into a prospective database. Inclusion criteria were rTKAs with concomitant TTO, without extensor mechanism allograft, and a minimum of two years’ follow-up. A total of 135 rTKAs were included, with a mean age of 65 years (SD 9.0) and a mean BMI of 29.8 kg/m. 2. (SD 5.7). The most frequent indications for revision were infection (50%; 68/135), aseptic loosening (25%; 34/135), and stiffness (13%; 18/135). Patients had standardized follow-up at six weeks, three months, six months, and annually thereafter. Complications and revisions were evaluated at the last follow-up. Functional outcomes were assessed using the Knee Society Score (KSS) and range of motion. Results. The mean follow-up was 51 months (SD 26; 24 to 121). Bony union was confirmed in 95% of patients (128/135) at a mean of 3.4 months (SD 2.7). The complication rate was 15% (20/135), consisting of nine tibial tubercle fracture displacements (6.7%), seven nonunions (5%), two delayed unions, one tibial fracture, and one wound dehiscence. Seven patients (5%) required eight revision procedures (6%): three bone grafts, three osteosyntheses, one extensor mechanism allograft, and one wound revision. The functional scores and flexion were significantly improved after surgery: mean KSS knee, 48.8 (SD 17) vs 79.6 (SD 20; p < 0.001); mean KSS function, 37.6 (SD 21) vs 70.2 (SD 30; p < 0.001); mean flexion, 81.5° (SD 33°) vs 93° (SD 29°; p = 0.004). Overall, 98% of patients (n = 132) had no extension deficit. The use of hinge implants was a significant risk factor for tibial tubercle fracture (p = 0.011). Conclusion. TTO during rTKA was an efficient procedure to improve knee exposure with a high union rate, but had significant specific complications. Functional outcomes were improved at mid term. Cite this article: Bone Joint J 2023;105-B(10):1078–1085


The Bone & Joint Journal
Vol. 106-B, Issue 9 | Pages 916 - 923
1 Sep 2024
Fricka KB Wilson EJ Strait AV Ho H Hopper, Jr RH Hamilton WG Sershon RA

Aims

The optimal bearing surface design for medial unicompartmental knee arthroplasty (UKA) remains controversial. The aim of this study was to compare outcomes of fixed-bearing (FB) and mobile-bearing (MB) UKAs from a single high-volume institution.

Methods

Prospectively collected data were reviewed for all primary cemented medial UKAs performed by seven surgeons from January 2006 to December 2022. A total of 2,999 UKAs were identified, including 2,315 FB and 684 MB cases. The primary outcome measure was implant survival. Secondary outcomes included 90-day and cumulative complications, reoperations, component revisions, conversion arthroplasties, range of motion, and patient-reported outcome measures. Overall mean age at surgery was 65.7 years (32.9 to 94.3), 53.1% (1,593/2,999) of UKAs were implanted in female patients, and demographics between groups were similar (p > 0.05). The mean follow-up for all UKAs was 3.7 years (0.0 to 15.6).


Bone & Joint Open
Vol. 4, Issue 10 | Pages 808 - 816
24 Oct 2023
Scott CEH Snowden GT Cawley W Bell KR MacDonald DJ Macpherson GJ Yapp LZ Clement ND

Aims

This prospective study reports longitudinal, within-patient, patient-reported outcome measures (PROMs) over a 15-year period following cemented single radius total knee arthroplasty (TKA). Secondary aims included reporting PROMs trajectory, 15-year implant survival, and patient attrition from follow-up.

Methods

From 2006 to 2007, 462 consecutive cemented cruciate-retaining Triathlon TKAs were implanted in 426 patients (mean age 69 years (21 to 89); 290 (62.7%) female). PROMs (12-item Short Form Survey (SF-12), Oxford Knee Score (OKS), and satisfaction) were assessed preoperatively and at one, five, ten, and 15 years. Kaplan-Meier survival and univariate analysis were performed.


The Bone & Joint Journal
Vol. 105-B, Issue 6 | Pages 635 - 640
1 Jun 2023
Karczewski D Siljander MP Larson DR Taunton MJ Lewallen DG Abdel MP

Aims

Knowledge on total knee arthroplasties (TKAs) in patients with a history of poliomyelitis is limited. This study compared implant survivorship and clinical outcomes among affected and unaffected limbs in patients with sequelae of poliomyelitis undergoing TKAs.

Methods

A retrospective review of our total joint registry identified 94 patients with post-polio syndrome undergoing 116 primary TKAs between January 2000 and December 2019. The mean age was 70 years (33 to 86) with 56% males (n = 65) and a mean BMI of 31 kg/m2 (18 to 49). Rotating hinge TKAs were used in 14 of 63 affected limbs (22%), but not in any of the 53 unaffected limbs. Kaplan-Meier survivorship analyses were completed. The mean follow-up was eight years (2 to 19).


Aims

The tibial component of total knee arthroplasty can either be an all-polyethylene (AP) implant or a metal-backed (MB) implant. This study aims to compare the five-year functional outcomes of AP tibial components to MB components in patients aged over 70 years. Secondary aims are to compare quality of life, implant survivorship, and cost-effectiveness.

Methods

A group of 130 patients who had received an AP tibial component were matched for demographic factors of age, BMI, American Society of Anesthesiologists (ASA) grade, sex, and preoperative Knee Society Score (KSS) to create a comparison group of 130 patients who received a MB tibial component. Functional outcome was assessed prospectively by KSS, quality of life by 12-Item Short-Form Health Survey questionnaire (SF-12), and range of motion (ROM), and implant survivorships were compared. The SF six-dimension (6D) was used to calculate the incremental cost effectiveness ratio (ICER) for AP compared to MB tibial components using quality-adjusted life year methodology.


The Bone & Joint Journal
Vol. 106-B, Issue 7 | Pages 680 - 687
1 Jul 2024
Mancino F Fontalis A Grandhi TSP Magan A Plastow R Kayani B Haddad FS

Aims

Robotic arm-assisted surgery offers accurate and reproducible guidance in component positioning and assessment of soft-tissue tensioning during knee arthroplasty, but the feasibility and early outcomes when using this technology for revision surgery remain unknown. The objective of this study was to compare the outcomes of robotic arm-assisted revision of unicompartmental knee arthroplasty (UKA) to total knee arthroplasty (TKA) versus primary robotic arm-assisted TKA at short-term follow-up.

Methods

This prospective study included 16 patients undergoing robotic arm-assisted revision of UKA to TKA versus 35 matched patients receiving robotic arm-assisted primary TKA. In all study patients, the following data were recorded: operating time, polyethylene liner size, change in haemoglobin concentration (g/dl), length of inpatient stay, postoperative complications, and hip-knee-ankle (HKA) alignment. All procedures were performed using the principles of functional alignment. At most recent follow-up, range of motion (ROM), Forgotten Joint Score (FJS), and Oxford Knee Score (OKS) were collected. Mean follow-up time was 21 months (6 to 36).


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 Bone & Joint Journal
Vol. 105-B, Issue 3 | Pages 269 - 276
1 Mar 2023
Tay ML Monk AP Frampton CM Hooper GJ Young SW

Aims

Unicompartmental knee arthroplasty (UKA) has higher revision rates than total knee arthroplasty (TKA). As revision of UKA may be less technically demanding than revision TKA, UKA patients with poor functional outcomes may be more likely to be offered revision than TKA patients with similar outcomes. The aim of this study was to compare clinical thresholds for revisions between TKA and UKA using revision incidence and patient-reported outcomes, in a large, matched cohort at early, mid-, and late-term follow-up.

Methods

Analyses were performed on propensity score-matched patient cohorts of TKAs and UKAs (2:1) registered in the New Zealand Joint Registry between 1 January 1999 and 31 December 2019 with an Oxford Knee Score (OKS) response at six months (n, TKA: 16,774; UKA: 8,387), five years (TKA: 6,718; UKA: 3,359), or ten years (TKA: 3,486; UKA: 1,743). Associations between OKS and revision within two years following the score were examined. Thresholds were compared using receiver operating characteristic analysis. Reasons for aseptic revision were compared using cumulative incidence with competing risk.


Bone & Joint Research
Vol. 11, Issue 8 | Pages 575 - 584
17 Aug 2022
Stoddart JC Garner A Tuncer M Cobb JP van Arkel RJ

Aims

The aim of this study was to determine the risk of tibial eminence avulsion intraoperatively for bi-unicondylar knee arthroplasty (Bi-UKA), with consideration of the effect of implant positioning, overstuffing, and sex, compared to the risk for isolated medial unicondylar knee arthroplasty (UKA-M) and bicruciate-retaining total knee arthroplasty (BCR-TKA).

Methods

Two experimentally validated finite element models of tibia were implanted with UKA-M, Bi-UKA, and BCR-TKA. Intraoperative loads were applied through the condyles, anterior cruciate ligament (ACL), medial collateral ligament (MCL), and lateral collateral ligament (LCL), and the risk of fracture (ROF) was evaluated in the spine as the ratio of the 95th percentile maximum principal elastic strains over the tensile yield strain of proximal tibial bone.


The Bone & Joint Journal
Vol. 96-B, Issue 12 | Pages 1631 - 1636
1 Dec 2014
Parkkinen M Madanat R Mäkinen TJ Mustonen A Koskinen SK Lindahl J

The role of arthroscopy in the treatment of soft-tissue injuries associated with proximal tibial fractures remains debatable. Our hypothesis was that MRI over-diagnoses clinically relevant associated soft-tissue injuries. This prospective study involved 50 consecutive patients who underwent surgical treatment for a split-depression fracture of the lateral tibial condyle (AO/OTA type B3.1). The mean age of patients was 50 years (23 to 86) and 27 (54%) were female. All patients had MRI and arthroscopy. Arthroscopy identified 12 tears of the lateral meniscus, including eight bucket-handle tears that were sutured and four that were resected, as well as six tears of the medial meniscus, of which five were resected. Lateral meniscal injuries were diagnosed on MRI in four of 12 patients, yielding an overall sensitivity of 33% (95% confidence interval (CI) 11 to 65). Specificity was 76% (95% CI 59 to 88), with nine tears diagnosed among 38 menisci that did not contain a tear. MRI identified medial meniscal injuries in four of six patients, yielding an overall sensitivity of 67% (95% CI 24 to 94). Specificity was 66% (95% CI 50 to 79), with 15 tears diagnosed in 44 menisci that did not contain tears. MRI appears to offer only a marginal benefit as the specificity and sensitivity for diagnosing meniscal injuries are poor in patients with a fracture. There were fewer arthroscopically-confirmed associated lesions than reported previously in MRI studies. Cite this article: Bone Joint J 2014;96-B:1631–6


The Bone & Joint Journal
Vol. 101-B, Issue 2 | Pages 227 - 232
1 Feb 2019
Walker T Rutkowski L Innmann M Panzram B Herre J Gotterbarm T Aldinger PR Merle C

Aims. The treatment of patients with allergies to metal in total joint arthroplasty is an ongoing debate. Possibilities include the use of hypoallergenic prostheses, as well as the use of standard cobalt-chromium (CoCr) alloy. This non-designer study was performed to evaluate the clinical outcome and survival rates of unicondylar knee arthroplasty (UKA) using a standard CoCr alloy in patients reporting signs of a hypersensitivity to metal. Patients and Methods. A consecutive series of patients suitable for UKA were screened for symptoms of metal hypersensitivity by use of a questionnaire. A total of 82 patients out of 1737 patients suitable for medial UKA reporting cutaneous metal hypersensitivity to cobalt, chromium, or nickel were included into this study and prospectively evaluated to determine the functional outcome, possible signs of hypersensitivity, and short-term survivorship at a minimum follow-up of 1.5 years. Results. At a mean follow-up of three years (1.5 to 5.7), no local or systemic symptoms of hypersensitivity to metal were observed. One patient underwent revision surgery to a bicondylar prosthesis due to a tibial periprosthetic fracture resulting in a survival rate of 98.8% (95% confidence interval (CI) 91.7 to 99.8; number at risk, 28) at three years with the endpoint of revision for any reason and a survival rate of 97.6% (95% CI 90.6 to 99.3; number at risk, 29) for the endpoint of all reoperations. Clinical outcome was good to excellent with a mean Oxford Knee Score of 42.5 (. sd. 2.5; 37 to 48). Conclusion. This study is the first demonstrating clinical results and survival analysis of UKA using a CoCr alloy in patients with a history of metal hypersensitivity. Functional outcome and survivorship are on a high-level equivalent to those reported for UKA in patients without a history of metal hypersensitivity. No serious local or systemic symptoms of metal hypersensitivity could be detected, and no revision surgery was performed due to an adverse reaction to metal ions


The Bone & Joint Journal
Vol. 103-B, Issue 6 Supple A | Pages 158 - 164
1 Jun 2021
Hernandez NM Hinton ZW Wu CJ Ryan SP Bolognesi MP

Aims

Tibial cones are often utilized in revision total knee arthroplasty (TKA) with metaphyseal defects. Because there are few studies evaluating mid-term outcomes with a sufficient cohort, the purpose of this study was to evaluate tibial cone survival and complications in revision TKAs with tibial cones at minimum follow-up of five years.

Methods

A retrospective review was completed from September 2006 to March 2015, evaluating 67 revision TKAs (64 patients) that received one specific porous tibial cone during revision TKA. The final cohort was composed of 62 knees (59 patients) with five years of clinical follow-up or reoperation. The mean clinical follow-up of the TKAs with minimum five-year clinical follow-up was 7.6 years (5.0 to 13.3). Survivorship analysis was performed with the endpoints of tibial cone revision for aseptic loosening, tibial cone revision for any reason, and reoperation. We also evaluated periprosthetic joint infection (PJI), risk factors for failure, and performed a radiological review.


Bone & Joint Open
Vol. 2, Issue 8 | Pages 638 - 645
1 Aug 2021
Garner AJ Edwards TC Liddle AD Jones GG Cobb JP

Aims

Joint registries classify all further arthroplasty procedures to a knee with an existing partial arthroplasty as revision surgery, regardless of the actual procedure performed. Relatively minor procedures, including bearing exchanges, are classified in the same way as major operations requiring augments and stems. A new classification system is proposed to acknowledge and describe the detail of these procedures, which has implications for risk, recovery, and health economics.

Methods

Classification categories were proposed by a surgical consensus group, then ranked by patients, according to perceived invasiveness and implications for recovery. In round one, 26 revision cases were classified by the consensus group. Results were tested for inter-rater reliability. In round two, four additional cases were added for clarity. Round three repeated the survey one month later, subject to inter- and intrarater reliability testing. In round four, five additional expert partial knee arthroplasty surgeons were asked to classify the 30 cases according to the proposed revision partial knee classification (RPKC) system.


The Bone & Joint Journal
Vol. 103-B, Issue 7 | Pages 1261 - 1269
1 Jul 2021
Burger JA Zuiderbaan HA Sierevelt IN van Steenbergen L Nolte PA Pearle AD Kerkhoffs GMMJ

Aims

Uncemented mobile bearing designs in medial unicompartmental knee arthroplasty (UKA) have seen an increase over the last decade. However, there are a lack of large-scale studies comparing survivorship of these specific designs to commonly used cemented mobile and fixed bearing designs. The aim of this study was to evaluate the survivorship of these designs.

Methods

A total of 21,610 medial UKAs from 2007 to 2018 were selected from the Dutch Arthroplasty Register. Multivariate Cox regression analyses were used to compare uncemented mobile bearings with cemented mobile and fixed bearings. Adjustments were made for patient and surgical factors, with their interactions being considered. Reasons and type of revision in the first two years after surgery were assessed.


The Journal of Bone & Joint Surgery British Volume
Vol. 89-B, Issue 2 | Pages 180 - 185
1 Feb 2007
Koëter S Diks MJF Anderson PG Wymenga AB

An abnormal lateral position of the tibial tuberosity causes distal malalignment of the extensor mechanism of the knee and can lead to lateral tracking of the patella causing anterior knee pain or objective patellar instability, characterised by recurrent dislocation. Computer tomography is used for a precise pre-operative assessment of the tibial tubercle-trochlear groove distance. A distance of more than 15 mm is considered to be pathological and an indication for surgery in symptomatic patients. In a prospective study we performed a subtle transfer of the tibial tuberosity according to the information gained from the pre-operative CT scan. This method was applied to two groups of patients, those with painful lateral tracking of the patella, and those with objective patellar instability. We evaluated the clinical results in 30 patients in each group. The outcome was documented at 3, 12 and 24 months using the Lysholm scale, the Kujala score, and a visual analogue pain score. Post-operatively, all but one patient in the instability group who had a patellar dislocation requiring further surgery reported good improvement with no further subluxation or dislocation. All patients in both groups had a marked improvement in pain and functional score. Two patients sustained a tibial fracture six and seven weeks after surgery. One patient suffered a per-operative fracture of the tibial tubercle which later required further fixation. If carefully performed, this type of transfer of the tibial tubercle appears to be a satisfactory technique for the treatment of patients with an increased tibial tubercle-trochlear groove distance and who present with symptoms related to lateral maltracking of the patella


Bone & Joint Open
Vol. 1, Issue 7 | Pages 339 - 345
3 Jul 2020
MacDessi SJ Griffiths-Jones W Harris IA Bellemans J Chen DB

Aims

An algorithm to determine the constitutional alignment of the lower limb once arthritic deformity has occurred would be of value when undertaking kinematically aligned total knee arthroplasty (TKA). The purpose of this study was to determine if the arithmetic hip-knee-ankle angle (aHKA) algorithm could estimate the constitutional alignment of the lower limb following development of significant arthritis.

Methods

A matched-pairs radiological study was undertaken comparing the aHKA of an osteoarthritic knee (aHKA-OA) with the mechanical HKA of the contralateral normal knee (mHKA-N). Patients with Grade 3 or 4 Kellgren-Lawrence tibiofemoral osteoarthritis in an arthritic knee undergoing TKA and Grade 0 or 1 osteoarthritis in the contralateral normal knee were included. The aHKA algorithm subtracts the lateral distal femoral angle (LDFA) from the medial proximal tibial angle (MPTA) measured on standing long leg radiographs. The primary outcome was the mean of the paired differences in the aHKA-OA and mHKA-N. Secondary outcomes included comparison of sex-based differences and capacity of the aHKA to determine the constitutional alignment based on degree of deformity.


The Bone & Joint Journal
Vol. 102-B, Issue 4 | Pages 458 - 462
1 Apr 2020
Limberg AK Tibbo ME Pagnano MW Perry KI Hanssen AD Abdel MP

Aims

Varus-valgus constrained (VVC) implants are often used during revision total knee arthroplasty (TKA) to gain coronal plane stability. However, the increased mechanical torque applied to the bone-cement interface theoretically increases the risk of aseptic loosening. We assessed mid-term survivorship, complications, and clinical outcomes of a fixed-bearing VVC device in revision TKAs.

Methods

A total of 416 consecutive revision TKAs (398 patients) were performed at our institution using a single fixed-bearing VVC TKA from 2007 to 2015. Mean age was 64 years (33 to 88) with 50% male (199). Index revision TKA diagnoses were: instability (n = 122, 29%), aseptic loosening (n = 105, 25%), and prosthetic joint infection (PJI) (n = 97, 23%). All devices were cemented on the epiphyseal surfaces. Femoral stems were used in 97% (n = 402) of cases, tibial stems in 95% (n = 394) of cases; all were cemented. In total, 93% (n = 389) of cases required a stemmed femoral and tibial component. Femoral cones were used in 29%, and tibial cones in 40%. Survivorship was assessed via competing risk analysis; clinical outcomes were determined using Knee Society Scores (KSSs) and range of movement (ROM). Mean follow-up was four years (2 to 10).