We compared lower limb coronal alignment measurements obtained pre- and post-operatively with long-leg radiographs and computer navigation in patients undergoing primary total knee replacement (TKR). A series of 185 patients had their pre- and post-implant radiological and computer-navigation system measurements of coronal alignment compared using the Bland-Altman method. The study included 81 men and 104 women with a mean age of 68.5 years (32 to 87) and a mean body mass index of 31.7 kg/m. 2. (19 to 49). Pre-implant Bland–Altman limits of agreement were -9.4° to 8.6° with a repeatability coefficient of 9.0°. The Bland–Altman plot showed a tendency for the radiological measurement to indicate a higher level of pre-operative deformity than the corresponding navigation measurement. Post-implant limits of agreement were -5.0° to 5.4° with a repeatability coefficient of 5.2°. The tendency for valgus knees to have greater deformity on the radiograph was still seen, but was weaker for varus knees. . The alignment seen or measured intra-operatively during TKR is not necessarily the same as the deformity seen on a standing long-leg radiograph either pre- or post-operatively. Further investigation into the effect of weight-bearing and surgical exposure of the joint on the mechanical femorotibial angle is required to enable the most appropriate intra-operative alignment to be selected

The results of primary total knee replacement performed on a group of haemophiliac patients in a single institution by the same surgeon using the same surgical technique and prosthesis are reported. A total of 35 primary replacements in 30 patients were carried out between 1996 and 2005 and were reviewed retrospectively. The mean age of the patients was 31 years (24 to 42) and the mean follow-up was for 7.5 years (1 to 10). There were 25 patients with haemophilia A and five with haemophilia B. The HIV status and CD4 count were recorded, and Knee Society scores determined. Two patients had inhibitors to the deficient coagulation factor. There were no early wound infections and only one late deep infection which required a two-stage revision arthroplasty, with a good final result. The incidence of infection in HIV-positive and negative patients was thus similar. One knee in a patient with inhibitor had excessive bleeding due to a pseudoaneurysm which required embolisation. The results were excellent in 27 knees (77%), good in six (17%) and fair in two (6%). The survival rate at 7.5 years taking removal of the prosthesis for loosening or infection as the end-point was 97%. The mechanical survival of total knee replacements in haemophiliacs is very good. Our results confirm that this is a reproducible procedure in haemophilia, even in HIV-positive patients with a CD4 count > 200 mm. 3. and those with inhibitors. Our rate of infection was lower than previously reported. This could be due to better control of the HIV status with highly active anti-retroviral therapy and the use of antibiotic-loaded cement

After total knee replacement a 57-year-old woman developed increasing pain in her left calf on exercise. This was due to erosion of the popliteal artery by a spur of cement. Removal of the spur with resection and Dacron grafting of the damaged section of the vessel cured her symptoms

Although patients with a history of venous thromboembolism (VTE) who undergo lower limb joint replacement are thought to be at high risk of further VTE, the actual rate of recurrence has not been reported. The purpose of this study was to identify the recurrence rate of VTE in patients who had undergone lower limb joint replacement, and to compare it with that of patients who had undergone a joint replacement without a history of VTE. . From a pool of 6646 arthroplasty procedures (3344 TKR, 2907 THR, 243 revision THR, 152 revision TKR) in 5967 patients (68% female, mean age 67.7; 21 to 96) carried out between 2009 and 2011, we retrospectively identified 118 consecutive treatment episodes in 106 patients (65% female, mean age 70; 51 to 88,) who had suffered a previous VTE. Despite mechanical prophylaxis and anticoagulation with warfarin, we had four recurrences by three months (3.4% of 118) and six by one year (5.1% of 118). In comparison, in all our other joint replacements the rate of VTE was 0.54% (35/6528). The relative risk of a VTE by 90 days in patients who had undergone a joint replacement with a history of VTE compared with those with a joint replacement and no history of VTE was 6.3 (95% confidence interval, 2.3 to 17.5). There were five complications in the previous VTE group related to bleeding or over-anticoagulation. Cite this article: Bone Joint J 2014;96-B:1515–19

Satisfactory selection criteria are essential for the successful outcome of unicompartmental knee arthroplasty (UCA). We report the frequency of revision of the Oxford medial unicompartmental arthroplasty in knees previously treated for anteromedial osteoarthritis by high tibial osteotomy (HTO). The combined results from three sources were used to allow statistical analysis of this uncommon subgroup. In the combined series of 631 knees (507 patients) which had medial unicompartmental replacement, 613 were primary procedures and 18 were for a failed HTO. The mean follow-up times of the two groups were similar (5.8 years and 5.4 years, respectively). At review, 19 (3.1%) of the primary procedures and five (27.8%) of those undertaken for a failed HTO had been revised to total knee replacement. Survival analysis revealed the ten-year cumulative survivals to be 96% and 66%, respectively. The log-rank comparison of these survivals revealed a highly significant difference (p < 0.0001). We recommend that the Oxford UCA should not be used in knees which have previously undergone an HTO

The treatment of infected nonunions is difficult. Antibiotic cement-coated (ACC) rods provide stability as well as delivering antibiotics. We conducted a review of 110 infected nonunions treated with ACC rods. Patients were divided into two groups: group A (67 patients) with an infected arthrodesis, and group B (43 patients) with an infected nonunion in a long bone. In group A, infected arthrodesis, the success rate after the first procedure was 38/67 (57%), 29/67 (43%) required further surgery for either control of infection or non-union. At last follow-up, five patients required amputation, representing a limb salvage rate of 62/67 (93%) overall. In all, 29/67 (43%) presented with a bone defect with a mean size of 6.78 cm (2 to 25). Of those with a bone defect, 13/29 (45%) required further surgery and had a mean size of defect of 7.2 cm (3.5 to 25). The cultures were negative in 17/67 (26%) and the most common organism cultured was methicillin-resistant staphylococcus aureus (MRSA) (23/67, (35%)). In group B, long bones nonunion, the success rate after the first procedure was 26/43 (60%), 17/43 (40%) required further surgery for either control of infection or nonunion. The limb salvage rate at last follow-up was 43/43 (100%). A total of 22/43 (51%) had bone defect with a mean size of 4.7 cm (1.5 to 11.5). Of those patients with a bone defect, 93% required further surgery with a mean size of defect of 5.4 cm (3 to 8.5). The cultures were negative in 10/43 (24%) and the most common organism cultured was MRSA, 15/43 (35%). ACC rods are an effective form of treatment for an infected nonunion, with an acceptable rate of complications.

Cite this article: Bone Joint J 2014; 96-B:1349–54

The purpose of this study was to investigate the effects of right leg restriction at the knee, ankle or both, on a driver’s braking times. Previous studies have not investigated the effects of knee restriction on braking performance. A total of 23 healthy drivers performed a series of emergency braking tests in a driving simulator in either an above-knee plaster cast, a below-knee cast, or in a knee brace with an increasing range of restriction. The study showed that total braking reaction time was significantly longer when wearing an above-knee plaster cast, a below-knee plaster cast or a knee brace fixed at 0°, compared with braking normally (p < 0.001). Increases in the time taken to move the foot from the accelerator to the brake accounted for some of the increase in the total braking reaction time. Unexpectedly, thinking time also increased with the level of restriction (p < 0.001). The increase in braking time with an above-knee plaster cast in this study would increase the stopping distance at 30 miles per hour by almost 3 m.

These results suggest that all patients wearing any lower-limb plaster cast or knee brace are significantly impaired in their ability to perform an emergency stop. We suggest changes to the legislation to prevent patients from driving with lower-limb plaster casts or knee braces.