The primary aim was to assess survival of the opening wedge high tibial osteotomy (HTO) for medial compartment osteoarthritis. The secondary aim was to identify independent predictors of early (before 12 years) conversion to total knee arthroplasty (TKA).

During the 18-year period (1994–2011) 111 opening wedge HTO were performed at the study centre. Mean patient age was 45 years (range 18–68) and the majority were male (84%). Mean follow-up was 12 (range 6–21) years. Failure was defined as conversion to TKA. Kaplan-Meier, Cox regression and receiver operating curve (ROC) analyses were performed.

Forty (36%) HTO failed at a mean follow-up of 6.3 (range 1–15) years. The five-year survival rate was 84% (95% confidence interval (CI) 82.6–85.4), 10-year rate 65% (95% CI 63.5–66.5) and 15-year rate 55% (95% CI 53.3–56.7). Cox regression analysis identified older age (p<0.001) and female gender (hazard ratio (HR) 2.37, 95% CI 1.06–5.33, p=0.04) as independent predictors of failure. ROC analysis identified a threshold age of 47 years above which the risk of failure increased significantly (area under curve 0.72, 95% CI 0.62–0.81, p<0.001). Cox regression analysis, adjusting for covariates, identified a significantly greater (HR 2.49, 95% CI 1.26–4.91, p=0.01) risk of failure in patients aged 47 years old or more.

The risk of early conversion to TKA after an opening wedge HTO is significantly increased in female patients and those older than 47 years old. These risk factors should be considered pre-operatively and discussed with patients when planning surgical intervention for isolated medial compartment osteoarthritis.

The Low Contact Stress (LCS) mobile-bearing total knee replacement (TKR) was designed to minimize polyethylene wear, aseptic loosening and osteolysis. However, registry data suggests there is a significantly greater revision rate associated with the LCS TKR.

The primary aim of this study was to assess long-term survivorship of the LCS implant. Secondary aims were to assess survival according to mechanism of failure and identify predictors of revision.

We retrospectively identified 1091 LCS TKRs that were performed between 1993 and 2006. There was incomplete data available 33 who were excluded. The mean age of the cohort was 69 (SD 9.2) years and there were 577 TKRs performed in females and 481 in males. Mean follow up was 14 years (SD 4.3).

There were 59 revisions during the study period: 14 for infection, 18 for instability, and 27 for polyethylene wear. 392 patients died during follow up. All cause survival at 10-year was 95% (95%CI 91.7–98.3) and at 15-year was 93% (95%CI 88.6–97.8). Survival at 10-years according to mechanism of failure was: infection 99% (95%CI 94–100%), instability 98% (95%CI 94–100%), and polyethylene wear 98% (95%CI92–100). Of the 27 with polyethylene wear only 19 had associated osteolysis requiring component revision, the other 8 had simple polyethylene exchanges. Cox regression analysis, adjusting for confounding variables, identified younger age was the only predictor of revision (hazard ratio 0.96, 95%CI 0.94–0.99, p=0.003).

The LCS TKR demonstrates excellent long-term survivorship with a low rate of revision for osteolysis, however the risk is increased in younger patients.

25–40% of unicompartmental knee replacement (UKR) revisions are performed for unexplained pain possibly secondary to elevated proximal tibial bone strain. This study investigates the effect of tibial component metal backing and polyethylene thickness on cancellous bone strain in a finite element model (FEM) of a cemented fixed bearing medial UKR, validated using previously published acoustic emission data (AE).

FEMs of composite tibiae implanted with an all-polyethylene tibial component (AP) and a metal backed one (MB) were created. Polyethylene of thickness 6–10mm in 2mm increments was loaded to a medial load of 2500N. The volume of cancellous bone exposed to <−3000 (pathological overloading) and <−7000 (failure limit) minimum principal (compressive) microstrain (µ∊) and >3000 and >7000 maximum principal (tensile) microstrain was measured.

Linear regression analysis showed good correlation between measured AE hits and volume of cancellous bone elements with compressive strain <−3000µ∊: correlation coefficients (R= 0.947, R2 = 0.847), standard error of the estimate (12.6 AE hits) and percentage error (12.5%) (p<0.001). AP implants displayed greater cancellous bone strains than MB implants for all strain variables at all loads. Patterns of strain differed between implants: MB concentrations at the lateral edge; AP concentrations at the keel, peg and at the region of load application. AP implants had 2.2 (10mm) to 3.2 (6mm) times the volume of cancellous bone compressively strained <−7000µ∊ than the MB implants. Altering MB polyethylene insert thickness had no effect. We advocate using caution with all-polyethylene UKR implants especially in large or active patients where loads are higher.

Joint registries report that 25–40% of UKR revisions are performed for pain. Proximal tibial strain and microdamage are possible causes of this “unexplained” pain. The aim of this study was to examine the effect of UKR implant design and material on proximal tibial cortical strain and cancellous microdamage.

Composite Sawbone tibias were implanted with cemented UKR components: 5 fixed bearing all-polyethylene (FB-AP), 5 fixed bearing metal backed (FB-MB), and 5 mobile bearing metal backed implants (MB-MB). Five intact tibias were used as controls. Tibias were loaded in 500N increments to 2500N. Cortical surface strain was measured using digital image correlation (DIC). Cancellous microdamage was measured using acoustic emission (AE), a technique which detects elastic waves produced by the rapid release of energy during microdamage events.

DIC showed significant differences in anteromedial cortical strain between implants at 1500N and 2500N in the proximal 10mm only (p<0.001) with strain shielding in metal backed implants. AE showed significant differences in cancellous microdamage (AE hits), between implants at all loads (p=0.001). FB-AP implants displayed significantly more hits at all loads than both controls and metal backed implants (p<0.001). FB-AP implants also differed significantly by displaying AE hits on unloading (p=0.01), reflecting a lack of implant stiffness. Compared to controls, the FB-AP implant displayed 15x the total AE hits, the FB-MB 6x and the MB-MB 2.7x. All-polyethylene medial UKR implants are associated with greater cancellous bone microdamage than metal backed implants even at low loads.

Unicompartmental knee replacements (UKRs) have inconsistent and variable survivorships reported in the literature. It has been suggested that many are revised for ongoing pain with no other mode of failure identified. Using a medial UKR with an all-polyethylene non-congruent tibial component from 2004–7, we noted a revision rate of 9/98 cases (9.2%) at a mean of 39 months. Subchondral sclerosis was noted under the tibial component in 3/9 revisions with well fixed implants, and the aim of this study was to investigate this as a mode of failure. 89 UKRs in 77 patients were investigated radiographically (at mean 50 months) and with SF-12 and Oxford Knee scores at mean follow up 55 months. Subjectively 23/89 cases (25%) had sclerosis under the tibial component. We describe a method of quantifying this sclerosis as a greyscale ratio (GSR), which was significantly correlated with presence/absence of sclerosis (p<0.001). Significant predictors of elevated GSR (increasing sclerosis) were female sex (p<0.001) and elevated BMI (P=0.010) on both univariate and multivariate analysis. In turn, elevated GSR was significantly associated with poorer improvement in OKS (p<0.05) at the time of final follow up. We hypothesise that this sclerosis results from repetitive microfracture and adaptive remodelling in the proximal tibia due to increased strain. Finite element analysis is required to investigate this further, but we suggest caution should be employed when considering all polyethylene UKR implants in older women and in those with BMI >35.

The aim of this study was to explore the pre-operative predictors of the function component of the WOMAC one year after total knee arthroplasty (TKA) using a hierarchical regression model.

The pre-operative and one year post-operative results of 71 patients with knee osteoarthritis who underwent TKA were analysed. First the correlation between the post-operative function component of the WOMAC and a range of pre-operative measures were calculated to determine the independent variables for the hierarchical regression model. Independent pre-operative measures which showed a significant correlation with post-operative function were then entered in the model. Pre-operative measures were divided into three types according to International Classification of Health: (i) Personal characteristics, (ii) body structures and function and (iii) Psychosocial variables.

The following pre-operative measures were correlated with post-operative function: Knee flexion (r=-0.254), extensor strength (r=-0.338), flexor strength (r=-0.257), mental health component of the SF36 (r=-0.304), Tampa scale (fear of movement), (r=0.261), the sense of helplessness due to pain (r=0.264) and Stanford arthritis Self-Efficacy Pain Scale (r=-0.343). This scale is a measure of the person's belief in their capability to cope with their arthritis pain. The higher the score the better the person's self-efficacy.

Only independent pre-operative measures were entered in the models. In step 0, we controlled for age and Body Mass Index (BMI), in step 1 we entered knee flexion and extensor strength (model 1) and in step 2 Self-Efficacy was entered in the model (model2). In model1 extensor strength was a significant predictor of post-operative function (beta =-0.242, p=0.028). In the final model (model3) pre-operative extensor strength (beta =-0.242, p=0.07) and Self-Efficacy (beta -0.266, p=0.046) were the strongest predictors of post-operative function.

Purpose

The aim of the present study was to look at survivorship and patient satisfaction of a fixed bearing unicompartmental knee arthroplasty with an all-polyethylene tibial component.

High flexion designs are intended to provide a greater range of knee flexion and possibly improve flexion in stiff knees. This study assessed the effects of two implant designs. A posterior stabilised high flexion mobile bearing (MB) design vs a cruciate retaining standard fixed bearing (FB) design.

The aim of this study was to assess whether implant design has an effect on the functional outcome one year after total knee arthroplasty (TKA).

This study aimed to answer the following two questions. Firstly, which activities do people waiting for a total knee arthroplasty rate as important? Secondly, does their self-rated performance of these activities improve after surgery?

The aim of this study was to investigate the pre-operative factors predicting the knee range of motion during stair ascending and descending a year after total knee arthroplasty.

The pre-operative and one year post-operative results of fifty six patients with osteoarthritis were analysed. Range of knee motion during stair ascent and descent was recorded using electrogoniometry. Pre-operative measures were grouped in three different domains; the Demographic Domain with age and Body Mass Index (BMI), the Body Function Domain with knee range of motion in long sitting (ROMsit), Knee extensor moment, Pain on a Visual Analogue Scale and the stiffness component of the Western Ontario McMaster University Osteoarthritis Index (WOMAC) and thirdly the Psychosocial Domain with the Tampa scale for ‘fear of movement’ (TSK) and the sense of helplessness due to pain. Hierarchical Multiple Regression was used to analyse the relative importance of measures grouped into the three domain blocks on range of motion of the operated knee during stair ascent and descent. Model 1 contained domain block 1, model 2 included domain blocks 1 and 2 and model 3 included domain blocks 1,2 and 3.

Learned helplessness was a significant predicting factor for stair descent (beta; −0.538, p=0.025) while for stair ascent, age (beta 0.375, p=0.005) and ROMsit (beta 0.365, p=0.021) were significant predicting variables.

These results show that postoperative stair ascent and descent are predicted by different pre-operative factors. For stair ascent the demographic factors age and function factor ROM are important, while for stair descent, only the addition of the psychosocial factors in model 3 resulted in a significant change. These results indicate that treatment of patients with end-stage osteoarthritis should not only be aimed at improving range of motion of the knee but should also take into account psychosocial variables such as a sense of helplessness due to pain.

The primary aim of this study was to investigate whether objective daily physical activity, measured using an activity monitor one year after Total Knee Arthroplasty was different from that measured before surgery.

An activity monitor (activPAL) which records the number of steps in addition to the time spent sitting or lying, standing and ‘stepping’ was used to quantify physical activity. Forty-five patients with osteoarthritis (average 69.8 years old) were assessed an average of 38 days before and 368 days after total knee arthroplasty-before. A group of 40 age matched controls were also recruited. In addition to objective daily physical activity, knee range of motion, pain using the visual analogue score and the Western Ontario McMaster University Osteoarthritis Index (WOMAC 3.1) were also recorded before and after surgery.

Patients reported a significant decrease in pain (54%, p< 0.001) and increase in function (62% p< 0.001) after surgery. However, measures of physical activity showed much smaller improvements which were mostly statistically non-significant. The number of steps taken on one day increased by 19% (from 6438 to 7634 steps, p=0.119) and time spent stepping increased from 7.9% to 8.7% (p=0.27). Only average cadence and estimated energy expenditure were statistically significantly higher after surgery, 8% improvement, p=0.003 and 8% improvement, p=0.026 respectively. Stepwise regression analysis showed that only 11.4% of the improvement in physical activity was due to the decrease in pain.

One year after TKA levels of physical activity were still significantly (p< 0.05) lower than those of a group of age matched controls. In conclusion, other factors not measured in this study are to a large part determining the amount of physical activity in patients after knee surgery. Future studies aiming to identify those factors are warranted.

The aim of this study was to investigate the effects of implant design and gender on the outcome of Total Knee Arthroplasty (TKA) in patients with osteoarthritis (OA).

In this double blind randomised controlled trial, patients with OA received either a standard posterior stabilised implant (n=28) or high flex version of this implant (n=28). Walking speed, knee flexion under anaesthesia (‘drop test’), knee flexion in sitting and during functional activities as measured by electrogoniometry, daily number of steps, Quality of Life (SF36), the function component of the Knee Society Score, pain (Visual Analogue Score) and extensor strength were measured before and one year after TKA.

Type of implant did not have a significant effect on any of the outcome measures recorded, while gender showed significant effects both before and after surgery. Before surgery, females had a significantly lower knee range of motion, (both passive and functional), lower Knee Score function component, walking speed and strength. After surgery they had a statistically significant lower range of knee motion during functional activities such as walking up and down a slope. Strength was also still significantly lower but post-operative self-reported function were similar for both genders. There was also no difference between male and female participants regarding Quality of life, objective daily physical activity or pain.

The results of this study showed that there is a clinically and statistically significant difference between the function of female and male patients both before and after total knee arthroplasty. Although female patients seem to benefit more from TKA than males, on average they do not achieve the same functional knee motion after surgery. Unlike gender, implant design did not influence the knee motion or function in this group of patients. This has important implications for future research and treatment planning in order to maximise the functional outcome after TKA.

Objective: To evaluate the impact of soft tissue release on range of movement following total knee replacement.

Methods: Sixty four patients underwent PFC sigma total knee replacement through a medial arthrotomy. Range of active movement was measured preoperatively, and maximal flexion was measured after implantation, using the drop test while the patient was under anaesthetic. Soft tissue release was graded from 1 to 5, depending on the structures released.

Range of movement was correlated with extent of soft tissue release, to see if release had any impact on increase in range of movement.

Results: All patients had an improvement in range of movement following surgery. Post operative range of movement correlated strongly with preoperative ROM.

Patients requiring extensive releases tended to have less preoperative ROM, but the gain was independent of medial release. Those requiring extensive posterior release had poorer preoperative movement, and significantly less improvement.

In those requiring an extensive medial release, a posterior release improved gain in ROM.

Conclusion: Postoperative ROM following TKR is independent of extent of medial release. In patients requiring extensive medial release, a posterior release improves gain in movement.

Objective: To evaluate the impact of soft tissue release on range of movement following total knee replacement.

Methods: Sixty four patients underwent next-gen (Zimmer) posterior stabilising total knee replacement through a medial arthrotomy. Range of active movement was measured preoperatively, and maximal flex-ion was measured after implantation, using the drop test while the patient was under anaesthetic. Soft tissue release was graded from 1 to 5, depending on the structures released.

Range of movement (ROM) was correlated with extent of soft tissue release, to see if release had any impact on increase in range of movement.

Results: All patients had an improvement in range of movement following surgery. Post operative range of movement correlated strongly with preoperative ROM. Patients requiring extensive releases tended to have less preoperative ROM, but the gain was independent of medial release. Those requiring extensive posterior release had poorer preoperative movement, and significantly less improvement.

In those requiring an extensive medial release, a posterior release improved gain in ROM.

Conclusion: Postoperative ROM following TKR is independent of extent of medial release. In patients requiring extensive medial release, a posterior release improves gain in movement.

Purpose: This study aims to explore the role of pain, fear of movement and learned helplessness on functional knee range of motion and daily functioning in a patients awaiting total knee arthroplasty (TKA)

Methods and results: Sixty-five patients (mean age 69 years old) with osteoarthritis were assessed an average of 37 days prior to TKA. Dynamic knee angle was measured during 11 functional activities including getting up from a chair and walking up and down a slope and stairs using flexible electrogoniometry. Function was assessed using the function components of the Knee Society Score (KSS) and the Western Ontario & McMaster University Osteoarthritis Index (WOMAC). Other self-report measures included the 8 item Tampa scale for kinesiophobia to assess ‘activity avoidance’ (TSK-AA), and the 5 item Helplessness subscale of the rheumatology attitudes index.

The pain component of the WOMAC was negatively associated with the knee angle during sitting down and getting up from a low chair and stepping in and out of a bath (r=0.40–0.45), but not with the peak knee angle during ascending and descending a slope or walking speed. Higher scores of the activity avoidance and the helplessness scales however, were associated with reduced knee angles during descending a slope and a slower walking speed (r=0.31–0.38). Both psychosocial scales were also associated with function (r=0.39–0.45). Another important finding was that activity avoidance was not associated with pain.

Conclusions: Not only pain but also fear of movement and learned helplessness play a role on specific components of knee function in patients with final stage osteoarthritis of the knee. Further research into the impact of pain and psychosocial variables on functional outcome in ostearthritis is indicated.

If an arthroplasty patient presents with wound breakdown, sinus formation or a hot, red joint the diagnosis of infection is straightforward. However, most total joint replacement (TJR) infections are difficult to distinguish from aseptic loosening. It is imperative to know if a painful TJR is infected to plan appropriate management.

In this prospective study of 204 patients we analysed the diagnostic accuracy of various tests for infection: Inflammatory Markers (CRP/ESR); Aspiration Microbiology; and the Polymerase Chain Reaction (PCR) – a novel technique in this situation. We used international criteria as the gold standard for infection, applied at the time of revision surgery. Any of – a sinus; frank pus in the wound; positive intra-operative microbiology; positive histology – classified the patient as infected. The sensitivity (Sens), specificity (Spec), positive predictive value (PPV) and negative predictive value (NPV) of each test were calculated.

52 patients with an original diagnosis of inflammatory arthritis were excluded, as histology may be inaccurate. The results for the remaining 152 patients are: CRP > 20mg/l: Sens 77%; Spec 76%; PPV 49%; NPV 92%. ESR > 30 mm/hr: Sens 61%; Spec 86%; PPV 57%; NPV 87%. Aspiration Microbiology: Sens 80%; Spec 83%; PPV 71%; NPV 88%. PCR: Sens 71%; Spec 78%; PPV 43%; NPV 89%.

Few patients with negative CRP/ESR were found to be infected; if positive, there was a 50/50 chance that the joint was infected. Positive aspiration microbiology was associated with underlying infection 3 times out of every 4, and negative results were correct 9 times out of 10. PCR was no more accurate than existing tests.

All patients with painful TJR’s should have inflammatory markers checked – if negative the clinician can be relatively reassured that the implant is not infected. If positive or suspicion remains, further investigation should be undertaken. Joint aspiration for microbiology is currently the best available second line investigation.

Introduction If an arthroplasty patient presents with wound breakdown, sinus formation or a hot, red, painful joint replacement the diagnosis of infection is relatively straightforward. However, most total joint replacement (TJR) infections present in an indolent fashion and are impossible to distinguish from aseptic loosening. It is imperative to know if pain in a TJR is due to infection to plan appropriate further management.

Methods In this prospective study of 204 patients we analysed the diagnostic accuracy of various tests for infection in the setting of TJR: Inflammatory Markers (CRP/ESR); Aspiration Microbiology; and the Polymerase Chain Reaction (PCR) – a novel technique in this situation. We used internationally agreed criteria as the gold standard for infection. The patient was deemed to be infected if any of the following were found at the time of revision surgery: a sinus; frank pus in the wound; positive microbiology or positive histology on intra-operative specimens. The sensitivity (Sens), specificity (Spec), positive predictive value (PPV) and negative predictive value (NPV) of each test were calculated.

Results 52 patients with an original diagnosis of inflammatory arthritis were excluded, as histology may be inaccurate. Their results have been presented elsewhere. The results for the remaining 152 patients are: CRP > 20mg/l: Sens 77%; Spec 76%; PPV 49%; NPV 92%. ESR > 30 mm/hr: Sens 61%; Spec 86%; PPV 57%; NPV 87%. Aspiration Microbiology: Sens 80%; Spec 83%; PPV 71%; NPV 88%. PCR: Sens 71%; Spec 78%; PPV 43%; NPV 89%.

Findings and Conclusions Only a few of the patients with negative inflammatory markers later turned out to be infected. If the inflammatory markers were positive, there was roughly a 50/50 chance that the joint was infected. Positive aspiration microbiology was associated with underlying infection approximately 3 times out of every 4, and negative results were correct 9 times out of 10. PCR was no more accurate than existing tests.

We recommend that all patients with painful TJRs have inflammatory markers checked as a screening test – if negative then the clinician can be relatively reassured that the implant is not infected. If positive, further investigation should be undertaken. Joint aspiration for microbiology is currently the best available second line investigation.

Aims: The results of surgical repair and reconstruction of knee dislocations were reviewed at average follow-up of 32 months. Methods: Twenty-one patients with 22 knee dislocations presented between 1994 and 2001. There was one vascular and one common peroneal nerve injury. Eight (38%) patients were treated in the acute period (< 14 days), the remainder were late reconstructions. The patients were evaluated at mean follow-up of 32 months (11 to 77). This included ROM measurement, clinical and instrumented ligament laxity testing. Posterior stress view with 10kg weight was used to evaluate the PCL reconstruction. Function was evaluated using the IKDC chart, the Lysholm Score and the Tegner Activity Level. Results: The mean Lysholm score in the acute group was 87 (range 81 to 93) and in the delayed group 75 (range 53 to 100), the mean Tegner activity rating was 5 in the acute group and 4.4 in the delayed group. IKDC assessment revealed no differences between the two patient groups. Instrumented testing of knee stability indicated better results for ACL reconstructions performed in the acute phase but no difference in the outcome of PCL reconstruction. There was no difference in loss of knee movement between the two groups. Conclusions: Good function can be obtained in the operatively treated knee dislocations at 1–7 years. Although the differences were small, the outcome in terms of overall knee function, activity levels and anterior tibial translation were better in those knees reconstructed within two weeks of injury.

We investigated the use of PCR (the Polymerase Chain Reaction) to detect the presence of infection in a group of patients undergoing revision arthroplasty for loose TJR (total joint replacement), compared to internationally agreed criteria used as the ‘gold standard’ for infection.

We prospectively tested samples taken from 108 patients undergoing revision arthroplasty (76 hips, 32 knees). Antibiotics were omitted prior to obtaining samples. DNA was extracted by 2 methods – a previously published technique (reference) and a commercial extraction kit (Qiagen^®). PCR involved amplification of an 882 base pair segment of the universal bacterial 16S RNA gene. During revision arthroplasty multiple specimens were taken from around the joint for microbiological and histological examination and the presence or absence of pus was noted. The patient was deemed to be infected if one of the following criteria was found: presence of a sinus pre-operatively; 2 or more intra-operative cultures positive for the same organism; an acute inflammatory response on histology; pus in the joint at revision.

Using the published DNA extraction technique PCR had a sensitivity of 50%, specificity of 93%, positive predictive value of 67% and negative predictive value of 88%. Using commercial extraction the sensitivity improved to 60%, specificity to 98%, positive predictive value to 90% and negative predictive value to 90%.

The previous report stated that PCR had a high sensitivity but a low specificity for detecting low grade infection. However, when using the published technique we found the opposite results – a moderate sensitivity and a high specificity. Introduction of a new DNA extraction technique improved the sensitivity. The refined PCR technique had a high accuracy, but further work is needed to improve sensitivity before we would recommend this method for routine clinical use.

We report on a minimum 5-year follow-up (mean 7 years) of 28 patients who underwent arthroscopically assisted ACL reconstruction using a patellar tendon graft. Knee function was assessed using Lysholm and Tegner scores and AP translation of the tibia was measured using a Stryker Laxity Tester, comparing the symptomatic with the normal knee. All measurements were made preoperatively and at the latest follow-up. In addition, all patients had standardised weight-bearing radiographs of the knee to assess joint space narrowing using the IKDC radiographic grading.

The mean preoperative Lysholm score of 71 (range 46–95) improved to 88 (range 57–100) at follow-up. The mean Tegner Activity score increased from 4.1 (range 1–6) to 7.2 (range 5–10). Preoperatively 17 patients had increased tibial translation of more than 5mm, 9 had 3–5mm and 2 had less than 3mm. At follow-up, 22 knees had less than 3mm tibial translation and 6 had 3–5mm. No patients had more than 5mm of tibial translation compared to the opposite knee. The IKDC radiographic grading of joint space narrowing revealed 14 patients with no narrowing, 11 with a joint space of more than 4mm and knees with a joint space of 2–4mm. Joint space narrowing was seen in patients who had partial or total meniscectomy before or at the time of ACL reconstruction.

These results indicate that the satisfactory outcome of ACL reconstruction using contemporary methods is maintained beyond 5 years. However, the 50% incidence of joint space narrowing associated with previous meniscectomy is a cause for concern.

We used electrogoniometers to measure the range of movement (ROM) of the knee during various activities, comparing 50 patients with osteoarthritis of the knee (OA) with 20 healthy age- and sex-matched subjects.

The minimum and maximum joint angles and the ranges of excursion of the patient and control groups were tested for significant differences, using an unrelated Student’s t-test with pooled variance. Knee flexion in patients with OA was significantly reduced during all activities (p < 0.05), but differences in knee extension were not significant except when patients negotiated stairs. We believe that this reduction in ROM is caused by inhibition due to pain when load-bearing. Static non-load-bearing measurements of the ROM poorly reflected the functional ROM, with a coefficient of determination (r²) of 0.59 in the patient group and 0.60 in the control group. Electrogoniometry of the ROM of the knee provides a reliable, accurate and objective measurement of knee function.

A series of 167 patients with Charnley-type total hip replacements were studied retrospectively to determine the incidence of trochanteric non-union, the degree of postoperative trochanteric displacement, and the relation between these two complications. The power in the hip abductor muscles, measured with a load-cell device, was significantly reduced if the trochanteric fragment had displaced proximally by more than 3 cm; 12% of those studied fell into this group and, as a consequence, had a poorer result. It was concluded that displacement of the trochanter was of greater importance than bony union in determining function in the replaced hip. Because these unwanted problems may compromise an otherwise successful operation, it is suggested tentatively that trochanteric osteotomy should be abandoned except for difficult primary operations or for revision procedures.