Aims

We studied the outcomes of hip and knee arthroplasties in a high-volume arthroplasty centre to determine if patients with morbid obesity (BMI ≥ 40 kg/m²) had unacceptably worse outcomes as compared to those with BMI < 40 kg/m².

Aims. We investigated changes in the axial alignment of the ipsilateral hip and knee after total hip arthroplasty (THA). . Patients and Methods. We reviewed 152 patients undergoing primary THA (163 hips; 22 hips in men, 141 hips in women) without a pre-operative flexion contracture. The mean age was 64 years (30 to 88). The diagnosis was osteoarthritis (OA) in 151 hips (primary in 18 hips, and secondary to dysplasia in 133) and non-OA in 12 hips. A posterolateral approach with repair of the external rotators was used in 134 hips and an anterior approach in 29 hips. We measured changes in leg length and offset on radiographs, and femoral anteversion, internal rotation of the hip and lateral patellar tilt on CT scans, pre- and post-operatively. . Results. The mean internal rotation increased by 11° (-15° to 46°) and was associated with underlying disease (OA), pre-operative range of internal rotation, gender, surgical approach, leg lengthening, and change of femoral anteversion (adjusted R. 2. : 0.253, p < 0.001). The mean lateral patellar tilt increased by 4° (-5° to 14°) and was associated with age, leg lengthening, and increment of hip internal rotation (adjusted R. 2. : 0.193, p < 0.001). Conclusion. Both internal rotation of the hip at rest and lateral patellar tilt are increased after THA. Changes in rotation after THA may affect gait, daily activities, the rate of dislocation of the hip, and ipsilateral knee pain. Take home message: Internal rotation of the hip at rest and lateral patellar tilt increase after THA. Cite this article: Bone Joint J 2016;98-B:349–58

Using general practitioner records and hospital notes and through direct telephone conversation with patients, we investigated the accuracy of nine patient-reported complications gathered from a self-completed questionnaire after elective joint replacement surgery of the hip and knee. A total of 402 post-discharge complications were reported after 8546 elective operations that were undertaken within a three-year period. These were reported by 136 men and 240 women with a mean age of 71.8 years (34 to 93). A total of 319 reported complications (79.4%; 95% confidence interval 75.4 to 83.3) were confirmed to be correct. High rates of correct reporting were demonstrated for infection (94.5%) and the need for further surgery (100%), whereas the rates of reporting deep-vein thrombosis (DVT), pulmonary embolism, myocardial infarction and stroke were lower (75% to 84.2%). Dislocation, peri-prosthetic fractures and nerve palsy had modest rates of correct reporting (36% to 57.1%). More patients who had knee surgery delivered incorrect reports of dislocation (p = 0.001) and DVT (p = 0.013).

Despite these variations, it appears that post-operative complications may form part of a larger patient-reported outcome programme after elective joint replacement surgery.

The lateral subvastus approach combined with an osteotomy of the tibial tubercle is a recognised, but rarely used approach for total knee replacement (TKR). A total of 32 patients undergoing primary TKR was randomised into two groups, in one of which the lateral subvastus approach combined with a tibial tubercle osteotomy and in the other the medial parapatellar approach were used. The patients were assessed radiologically and clinically using measurement of the range of movement, a visual analogue patient satisfaction score, the Western Ontario McMasters University Osteoarthritis Index and the American Knee Society score. Four patients were lost to the complete follow-up at two years.

At two years there were no significant differences between the groups in any of the parameters for clinical outcome. In the lateral approach group there was one complication due to displacement of the tibial tubercle osteotomy and two osteotomies took more than six months to unite. In the medial approach group, one patient had a partial tear of the quadriceps. There was a significantly greater incidence of lateral patellar subluxation in the medial approach group (3 of 12) compared with the lateral approach group (0 of 16) (p = 0.034), but without any apparent clinical detriment.

We conclude that the lateral approach with tibial tubercle osteotomy is a safe technique with an outcome comparable with that of the medial parapatellar approach for TKR, but the increased surgical time and its specific complications do not support its routine use. It would seem to be more appropriate to reserve this technique for patients in whom problems with patellar tracking are anticipated.

We audited the relationship between obesity and the age at which hip and knee replacement was undertaken at our centre. The database was analysed for age, the Oxford hip or knee score and the body mass index (BMI) at the time of surgery. In total, 1369 patients were studied, 1025 treated by hip replacement and 344 by knee replacement. The patients were divided into five groups based on their BMI (normal, overweight, moderately obese, severely obese and morbidly obese).

The difference in the mean Oxford score at surgery was not statistically significant between the groups (p > 0.05). For those undergoing hip replacement, the mean age of the morbidly obese patients was ten years less than that of those with a normal BMI. For those treated by knee replacement, the difference was 13 years. The age at surgery fell significantly for those with a BMI > 35 kg/m² for both hip and knee replacement (p > 0.05). This association was stronger for patients treated by knee than by hip replacement.