The emergence of minimally-invasive total knee replacement (TKR) has led to the refinement of several surgical approaches, including the quadriceps-sparing and sub-vastus. There is some disagreement as to the precise definition of the term ‘minimally-invasive’, especially in regard to the preservation of vastus medialis obliquus (VMO). It is known that the termination of VMO is variable and may make these approaches difficult. We have attempted to assess the factors influencing the insertion of VMO and the impact which they have on the approach for TKR. The MR scans of 198 knees were examined to assess the variation in the insertion of VMO in relation to the patella and the effect of variables such as age, gender and the presence of concurrent osteoarthritis of the knee on the insertion. Our findings showed that both age and the presence of osteoarthritis were contributing factors to changes in the level of insertion of VMO. Therefore, not all capsular incisions which extend proximal to the midpole of the patella will violate the quadriceps tendon

The purposes of this study were to define the range of laxity of the interosseous ligaments in cadaveric wrists and to determine whether this correlated with age, the morphology of the lunate, the scapholunate (SL) gap or the SL angle. We evaluated 83 fresh-frozen cadaveric wrists and recorded the SL gap and SL angle. Standard arthroscopy of the wrist was then performed and the grades of laxity of the scapholunate interosseous ligament (SLIL) and the lunotriquetral interosseous ligament (LTIL) and the morphology of the lunate were recorded. Arthroscopic evaluation of the SLIL revealed four (5%) grade I specimens, 28 (34%) grade II, 40 (48%) grade III and 11 (13%) grade IV. Evaluation of the LTIL showed 17 (20%) grade I specimens, 40 (48%) grade II, 28 (30%) grade III and one (1%) grade IV. On both bivariate and multivariate analysis, the grade of both the SLIL and LTIL increased with age, but decreased with female gender. The grades of SLIL or LTIL did not correlate with the morphology of the lunate, the SL gap or the SL angle. The physiological range of laxity at the SL and lunotriquetral joints is wider than originally described. The intercarpal ligaments demonstrate an age-related progression of laxity of the SL and lunotriquetral joints. There is no correlation between the grades of laxity of the SLIL or LTIL and the morphology of the lunate, the SL gap or the SL grade. Based on our results, we believe that the Geissler classification has a role in describing intercarpal laxity, but if used alone it cannot adequately diagnose pathological instability. We suggest a modified classification with a mechanism that may distinguish physiological laxity from pathological instability

This study compared the demographic, clinical and patient-reported outcomes after total hip replacement (THR) and Birmingham Hip Resurfacing (BHR) carried out by a single surgeon. Patients completed a questionnaire that included the WOMAC, SF-36 scores and comorbid medical conditions. Data were collected before operation and one year after. The outcome scores were adjusted for age, gender, comorbid conditions and, at one year, for the pre-operative scores. There were 214 patients with a THR and 132 with a BHR. Patients with a BHR were significantly younger (49 vs 67 years, p < 0.0001), more likely to be male (68% vs 42% of THR, p < 0.0001) and had fewer comorbid conditions (1.3 vs 2.0, p < 0.0001). Before operation there was no difference in WOMAC and SF-36 scores, except for function, in which patients awaiting THR were worse than those awaiting a BHR. At one year patients with a BHR reported significantly better WOMAC pain scores (p = 0.04) and in all SF-36 domains (p < 0.05). Patients undergoing BHR report a significantly greater improvement in general health compared with those with a THR

A retrospective study was conducted to investigate the changes in metal ion levels in a consecutive series of Birmingham Hip Resurfacings (BHRs) at a minimum ten-year follow-up. We reviewed 250 BHRs implanted in 232 patients between 1998 and 2001. Implant survival, clinical outcome (Harris hip score), radiographs and serum chromium (Cr) and cobalt (Co) ion levels were assessed. Of 232 patients, 18 were dead (five bilateral BHRs), 15 lost to follow-up and ten had been revised. The remaining 202 BHRs in 190 patients (136 men and 54 women; mean age at surgery 50.5 years (17 to 76)) were evaluated at a minimum follow-up of ten years (mean 10.8 years (10 to 13.6)). The overall implant survival at 13.2 years was 92.4% (95% confidence interval 90.8 to 94.0). The mean Harris hip score was 97.7 (median 100; 65 to 100). Median and mean ion levels were low for unilateral resurfacings (Cr: median 1.3 µg/l, mean 1.95 µg/l (< 0.5 to 16.2); Co: median 1.0 µg/l, mean 1.62 µg/l (< 0.5 to 17.3)) and bilateral resurfacings (Cr: median 3.2 µg/l, mean 3.46 µg/l (< 0.5 to 10.0); Co: median 2.3 µg/l, mean 2.66 µg/l (< 0.5 to 9.5)). In 80 unilateral BHRs with sequential ion measurements, Cr and Co levels were found to decrease significantly (p < 0.001) from the initial assessment at a median of six years (4 to 8) to the last assessment at a median of 11 years (9 to 13), with a mean reduction of 1.24 µg/l for Cr and 0.88 µg/l for Co. Three female patients had a > 2.5 µg/l increase of Co ions, associated with head sizes ≤ 50 mm, clinical symptoms and osteolysis. Overall, there was no significant difference in change of ion levels between genders (Cr, p = 0.845; Co, p = 0.310) or component sizes (Cr, p = 0.505; Co, p = 0.370). Higher acetabular component inclination angles correlated with greater change in ion levels (Cr, p = 0.013; Co, p = 0.002). Patients with increased ion levels had lower Harris hip scores (p = 0.038). In conclusion, in well-functioning BHRs the metal ion levels decreased significantly at ten years. An increase > 2.5 µg/l was associated with poor function. Cite this article: Bone Joint J 2013;95-B:1332–8

This study was designed to provide normal reference values for the centre-edge angle of Wiberg in the Chinese population by measuring 1494 radiographs according to the criteria of Tönnis. The mean angle was 23.1° (4.7° to 46.4°) in childhood (four to nine years), increasing to 28.9° (6° to 48°) in adolescence (10 to 18 years) and reaching 32.8° (13.7° to 58.8°) in adults. The angle was positively correlated with age, increasing by a mean of 0.78° annually before adulthood and by 0.070° annually in adults. A relative upward tendency after middle age might contribute to degenerative changes. No gender difference was discovered. The change in the angle with age was similar to that observed in other ethnic groups, showing moderate differences in the average of individual age groups, but the ethnic differences are not sufficient to explain the variation of incidence of developmental dysplasia of the hip in different races

The outcome in 83 patients with congenital clubfoot was evaluated at a mean age of 64 years using three validated questionnaires assessing both quality of life (short-form (SF)-36 and EQ-5D) and foot and ankle function (American Academy of Orthopaedic Surgeons (AAOS) Foot and Ankle questionnaire). In SF-36, male patients scored significantly better than male norms in seven of the eight domains, whereas female patients scored significantly worse than female norms in two of the eight. Male patients scored better than male norms in both the EQ-5D index (p = 0.027) and visual analogue scale (VAS) (p = 0.013), whereas female patients scored worse than female norms in the VAS (p < 0.001). Both male and female patients had a significantly worse outcome on the AAOS Core Scale than did norms. There was a significant correlation for both genders between the SF-36 Physical Component Summary Score and the AAOS Core Scale. The influence on activities of daily life was limited to foot and ankle problems in all patients, and in females there was an adverse effect in physical aspects of quality of life

Despite excellent results, the use of cemented total hip replacement (THR) is declining. This retrospective cohort study records survival time to revision following primary cemented THR using the most common combination of components that accounted for almost a quarter of all cemented THRs, exploring risk factors independently associated with failure. All patients with osteoarthritis who had an Exeter V40/Contemporary THR (Stryker) implanted before 31 December 2010 and recorded in the National Joint Registry for England and Wales were included in the analysis. Cox’s proportional hazard models were used to analyse the extent to which risk of revision was related to patient, surgeon and implant covariates, with a significance threshold of p < 0.01. A total of 34 721 THRs were included in the study. The overall seven-year rate of revision for any reason was 1.70% (99% confidence interval (CI) 1.28 to 2.12). In the final adjusted model the risk of revision was significantly higher in THRs with the Contemporary hooded component (hazard ratio (HR) 1.88, p < 0.001) than with the flanged version, and in smaller head sizes (< 28 mm) compared with 28 mm diameter heads (HR 1.50, p = 0.005). The seven-year revision rate was 1.16% (99% CI 0.69 to 1.63) with a 28 mm diameter head and flanged component. The overall risk of revision was independent of age, gender, American Society of Anesthesiologists grade, body mass index, surgeon volume, surgical approach, brand of cement/presence of antibiotic, femoral head material (stainless steel/alumina) and stem taper size/offset. However, the risk of revision for dislocation was significantly higher with a ‘plus’ offset head (HR 2.05, p = 0.003) and a hooded acetabular component (HR 2.34, p < 0.001). In summary, we found that there were significant differences in failure between different designs of acetabular component and sizes of femoral head after adjustment for a range of covariates

Operative release for entrapment of the suprascapular nerve was carried out in 35 patients. They were assessed at an average of 30 months (12 to 98) after operation using the functional shoulder score devised by Constant and Murley. The average age at the time of surgery was 40 years (17 to 67). Entrapment was due to injury in ten patients and no cause was found in three; 34 had diffuse posterolateral shoulder pain. The strength of abduction was reduced in all the patients. The average Constant score, unadjusted for age or gender, before operative release was 47% (28 to 53). In 25 of the patients both the supraspinatus and infraspinatus muscles were atrophied and seven had isolated atrophy of the infraspinatus muscle. The average conduction time from Erb’s point to the supraspinatus muscle and to the infraspinatus muscle was 5.7 ms (2.8 to 12.8) and 7.4 ms (3.4 to 13.4), respectively. In two patients MRI revealed a ganglion in the infraspinatus fossa and, in another, a complete rupture of the rotator cuff. The average time from the onset of symptoms to operation was ten months (3 to 36). A posterior approach was advocated. The average Constant score, after operative release, unadjusted for age or gender was 77% (35 to 91). The overall result was excellent in ten of the patients, very good in seven, good in 14, fair in two, and poor in two. The symptomatic and functional outcome in our series confirmed the usefulness and safety of operative decompression for entrapment of the suprascapular nerve

We assessed the medium-term outcome of three methods of isolated calf lengthening in cerebral palsy by clinical examination, observational gait analysis and, where appropriate, instrumented gait analysis. The procedures used were percutaneous lengthening of tendo Achillis, open Z-lengthening of tendo Achillis and lengthening of the gastrosoleus aponeurosis (Baker’s procedure). We reviewed 195 procedures in 134 children; 45 had hemiplegia, 65 diplegia and 24 quadriplegia. We established the incidence of calcaneus and recurrent equinus and identified ‘at-risk’ groups for each. At follow-up, 42% had satisfactory calf length, 22% had recurrent equinus and 36% calcaneus. The incidence of calcaneus in girls at follow-up was significantly higher (p = 0.002) while boys had an increased rate of recurrent equinus (p = 0.012). Children with diplegia who had surgery when aged eight years or younger had a 44% risk of calcaneus, while those over eight years had a 19% risk (p = 0.046). Percutaneous lengthening of tendo Achillis in diplegia was the least predictable, only 38% having a satisfactory outcome compared with 50% in the other procedures. The incidence of recurrent equinus in hemiplegic patients was 38%. Only 4% developed calcaneus. The type of surgery did not influence the outcome in patients with hemiplegia or quadriplegia. Severity of involvement, female gender, age at operation of less than eight years and percutaneous lengthening of tendo Achillis were ‘risk factors’ for calcaneus. Hemiplegia, male gender, and an aponeurosis muscle lengthening increased the risk of recurrent equinus

We conducted a longitudinal study including patients with the same type of primary hybrid total hip replacement and evaluated patient activity and femoral osteolysis at either five or ten years post-operatively. Activity was measured using the University of California, Los Angeles scale. The primary outcome was the radiological assessment of femoral osteolysis. Secondary outcomes were revision of the femoral component for aseptic loosening and the patients’ quality of life. Of 503 hip replacements in 433 patients with a mean age of 67.7 years (30 to 91), 241 (48%) were seen at five and 262 (52%) at ten years post-operatively. Osteolytic lesions were identified in nine of 166 total hip replacements (5.4%) in patients with low activity, 21 of 279 (7.5%) with moderate activity, and 14 of 58 (24.1%) patients with high activity. The risk of osteolysis increased with participation in a greater number of sporting activities. In multivariate logistic regression adjusting for age, gender, body mass index and the inclination angle of the acetabular component, the adjusted odds ratio for osteolysis comparing high vs moderate activity was 3.6 (95% confidence interval 1.6 to 8.3). Stratification for the cementing technique revealed that lower quality cementing increased the effect of high activity on osteolysis. Revision for aseptic loosening was most frequent with high activity. Patients with the highest activity had the best outcome and highest satisfaction. In conclusion, of patients engaged in high activity, 24% had developed femoral osteolysis five to ten years post-operatively

Studies describing the effect of body mass index (BMI) on the outcome of total hip replacement have been inconclusive and contradictory. We examined the effect of BMI on medium-term outcome in a cohort of 1617 patients who underwent a primary total hip replacement for osteoarthritis. These patients were followed prospectively for five years with the outcomes of dislocation, revision, duration of surgery and deep and superficial infection studied, as well as collecting Harris hip scores (HHS) and Short-Form 36 (SF-36) questionnaires pre-operatively and at review. A multivariate analysis was performed to see whether BMI is an independent predictor of poor outcome. We found that patients with a BMI of ? 35 kg/m. 2. have a 4.42 times higher rate of dislocation than those with a BMI < 25 kg/m. 2. Increasing BMI is also associated with superficial infection and poorer HHS and SF-36 scores at five years. These trends remain significant even when multivariate analysis adjusts for age, gender, prosthesis, operating consultant, pre-operative HHS and SF-36, and comorbidities including diabetes mellitus, cardiac disease and osteoporosis. Despite the increased risks, the five-year outcome scores indicate that obese patients have much to gain from total hip replacement. Thus total hip replacement should not be withheld from patients solely on the grounds of an elevated BMI. However, longer-term follow-up of this cohort is required to establish whether adverse outcomes become more evident with time

We investigated the pre-operative and one-year post-operative health-related quality of life (HRQoL) outcome by using a Euroqol (EQ-5D) questionnaire in 230 patients who underwent surgery for lumbar spinal stenosis. Data were obtained from the National Swedish Registry for operations on the lumbar spine between 2001 and 2002. We analysed the pre- and postoperative quality of life data, age, gender, smoking habits, pain and walking ability. The relative differences were compared to a Swedish EQ-5D population survey. The mean age of the patients was 66 years, and there were 123 females (53%). Before the operation 62 (27%) of the patients could walk more than 500 m. One year after the operation 150 (65%) were able to walk 500 m or more. The mean EQ-5D score improved from 0.36 to 0.64, and the HRQoL improved in 184 (80%) of the patients. However, they did not reach the level reported by a matched population sample (mean difference 0.18). Women had lower pre- and post-operative EQ-5D scores than men. Severe low back pain was a predictor for a poor outcome

We investigated the relationship between a number of patient and management variables and mortality after surgery for fracture of the hip. Data relating to 18 817 patients were obtained from the Scottish Hip Fracture Audit database. We divided variables into two categories, depending on whether they were case-mix (age; gender; fracture type; pre-fracture residence; pre-fracture mobility and ASA scores) or management variables (time from fracture to surgery; time from admission to surgery; grade of surgical and anaesthetic staff undertaking the procedure and anaesthetic technique). Multivariate logistic regression analysis showed that all case-mix variables were strongly associated with post-operative mortality, even when controlling for the effects of the remaining variables. Inclusion of the management variables into the case-mix base regression model provided no significant improvement to the model. Patient case-mix variables have the most significant effect on post-operative mortality and unfortunately such variables cannot be modified by pre-operative medical interventions

Current analysis of unicondylar knee replacements (UKRs) by national registries is based on the pooled results of medial and lateral implants. Consequently, little is known about the differential performance of medial and lateral replacements and the influence of each implant type within these pooled analyses. Using data from the National Joint Registry for England and Wales (NJR) we aimed to determine the proportion of UKRs implanted on the lateral side of the knee, and their survival and reason for failure compared with medial UKRs. By combining information on the side of operation with component details held on the NJR, we were able to determine implant laterality (medial versus lateral) for 32 847 of the 35 624 unicondylar replacements (92%) registered before December 2010. Of these, 2052 (6%) were inserted on the lateral side of the knee. The rates of survival at five years were 93.1% (95% confidence interval (CI) 92.7 to 93.5) for medial and 93.0% (95% CI 91.1 to 94.9) for lateral UKRs (p = 0.49). The rates of failure remained equivalent after adjusting for patient age, gender, American Society of Anesthesiologists (ASA) grade, indication for surgery and implant design using Cox’s proportional hazards method (hazard ratio for lateral relative to medial replacement = 0.88 (95% CI 0.69 to 1.13); p = 0.32). Aseptic loosening/lysis and unexplained pain were the main reasons for revision in both groups, although the reasons did vary depending on whether a mobile- or a fixed-bearing design was used. At a maximum of eight years the mid-term survival rates of medial and lateral UKRs are similar

We evaluated the concentrations of chromium and cobalt ions in blood after metal-on-metal surface replacement arthroplasty using a wrought-forged, high carbon content chromium-cobalt alloy implant in 64 patients. At one year, mean whole blood ion levels were 1.61 μg/L (0.4 to 5.5) for chromium and 0.67 μg/L (0.23 to 2.09) for cobalt. The pre-operative ion levels, component size, female gender and the inclination of the acetabular component were inversely proportional to the values of chromium and/or cobalt ions at one year postoperatively. Other factors, such as age and level of activity, did not correlate with the levels of metal ions. We found that the levels of the ions in the serum were 1.39 and 1.37 times higher for chromium and cobalt respectively than those in the whole blood. The levels of metal ions obtained may be specific to the hip resurfacing implant and reflect its manufacturing process

We describe injuries to the posterior root of the medial meniscus in patients with spontaneous osteonecrosis of the medial compartment of the knee. We identified 30 consecutive patients with spontaneous osteonecrosis of the medial femoral condyle. The radiographs and MR imaging were reviewed. We found tears of the posterior root of the medial meniscus in 24 patients (80%). Of these, 15 were complete and nine were partial. Complete tears were associated with > 3 mm of meniscal extrusion. Neither the presence of a root tear nor the volume of the osteonecrotic lesion were associated with age, body mass index (BMI), gender, side affected, or knee alignment. The grade of osteoarthritis was associated with BMI. Although tears of the posterior root of the medial meniscus were frequently present in patients with spontaneous osteonecrosis of the knee, this does not prove cause and effect. Further study is warranted

Peri-prosthetic femoral fracture after total hip replacement (THR) is associated with a poor outcome and high mortality. However, little is known about its long-term incidence after uncemented THR. We retrospectively reviewed a consecutive series of 326 patients (354 hips) who had received a CLS Spotorno replacement with an uncemented, straight, collarless tapered titanium stem between January 1985 and December 1989. The mean follow-up was 17 years (15 to 20). The occurrence of peri-prosthetic femoral fracture during follow-up was noted. Kaplan-Meier survival analysis was used to estimate the cumulative incidence of fracture. At the last follow-up, 86 patients (89 hips) had died and eight patients (eight hips) had been lost to follow-up. A total of 14 fractures in 14 patients had occurred. In ten hips, the femoral component had to be revised and in four the fracture was treated by open reduction and internal fixation. The cumulative incidence of peri-prosthetic femoral fracture was 1.6% (95% confidence interval 0.7 to 3.8) at ten years and 4.5% (95% confidence interval 2.6 to 8.0) at 17 years after the primary THR. There was no association between the occurrence of fracture and gender or age at the time of the primary replacement. Our findings indicate that peri-prosthetic femoral fracture is a significant mode of failure in the long term after the insertion of an uncemented CLS Spotorno stem. Revision rates for this fracture rise in the second decade. Further research is required to investigate the risk factors involved in the occurrence of late peri-prosthetic femoral fracture after the implantation of any uncemented stem, and to assess possible methods of prevention

Aims

Unicompartmental knee arthroplasty (UKA) and bicompartmental knee arthroplasty (BCA) have been associated with improved functional outcomes compared to total knee arthroplasty (TKA) in suitable patients, although the reason is poorly understood. The aim of this study was to measure how the different arthroplasties affect knee extensor function.

The management of the patella during total knee replacement is controversial. In some studies the absence of patellar resurfacing results in residual anterior knee pain in over 10% of patients. One form of treatment which may be used in an endeavour to reduce this is circumferential patellar rim electrocautery. This is believed to partially denervate the patella. However, there is no evidence of the efficacy of this procedure, nor do we know if it results in harm. A retrospective comparative cohort study was performed of 192 patients who had undergone a primary total knee replacement with the porous coated Low Contact Stress rotating platform prosthesis without patellar resurfacing between 2003 and 2007. In 98 patients circumferential electrocautery of the patellar rim was performed and in 94 patients it was not. The two groups were matched for gender and age. The general Oxford Knee Score and the more specific patellar score for anterior knee pain were used to assess patient outcomes a minimum of two years post-operatively. No statistically significant differences were noted between the groups for either scoring system (p = 0.41 and p = 0.87, respectively). Electrocautery of the patella rim did not improve the outcome scores after primary total knee replacement in our patients

The rate and mode of early failure in 463 Birmingham hip resurfacings in a two-centre, multisurgeon series were examined. Of the 463 patients two have died and three were lost to follow-up. The mean radiological and clinical follow-up was for 43 months (6 to 90). We have revised 13 resurfacings (2.8%) including seven for pain, three for fracture, two for dislocation and another for sepsis. Of these, nine had macroscopic and histological evidence of metallosis. The survival at five years was 95.8% (95% confidence interval (CI) 94.1 to 96.8) for revision for all causes and 96.9% (95% CI 95.5 to 98.3) for metallosis. The rate of metallosis related revision was 3.1% at five years. Risk factors for metallosis were female gender, a small femoral component, a high abduction angle and obesity. We do not advocate the use of the Birmingham Hip resurfacing procedure in patients with these risk factors