No clinical difference between fixed- and mobile-bearing cruciate-retaining total knee arthroplasty: a prospective randomized study.

PURPOSE: It is hypothesized that mobile polyethylene bearings in total knee arthroplasty (TKA) may confer benefits with regard to range of motion and have improved clinical outcome scores in comparison with an arthroplasty with a fixed-bearing design. Our study compares clinical outcomes between patients who undergo TKA with either a rotating platform or fixed bearing using a posterior cruciate-retaining design. METHODS: Three hundred and thirty-one patients were randomized to receive either a rotating-platform (161 patients) or a fixed-bearing (170 patients) implant. All patients were assessed pre-operatively and at 1 and 2 years post-operatively using standard tools (range of movement, Oxford Knee Score, American Knee Society Score, SF12 and Patella Score). RESULTS: There was no difference in pre- to 2-year post-operative outcomes between the groups with regard to improvement in range of motion (10° ± 16 vs. 9° ± 15), improvement in Oxford Knee Score (-17.6 ± 9.9 vs. -19.1 ± 8.4), improvement in American Knee Society Score (49.5 ± 24.7 vs. 50.7 ± 21.0), function (23.6 ± 19.6 vs. 25.0 ± 22.5) and pain (34.9 ± 16.2 vs. 35.8 ± 14.1) subscores, improvement in SF12 Score (10.0 ± 16.3 vs. 12.3 ± 15.8) or improvement in Patella Score (9.7 ± 7.4 vs. 10.6 ± 7.1). CONCLUSION: No difference was demonstrated in clinical outcome between patients with a rotating-platform and fixed-bearing posterior cruciate-retaining TKA at 2-year follow-up. LEVEL OF EVIDENCE: I.

Cemented polyethylene and cementless porous-coated acetabular components have similar outcomes at a mean of seven years after total hip replacement: a prospective randomised study.

The aim of this prospective randomised study was to compare the clinical and radiological results of a cemented all-polyethylene Ultima acetabular component with those of a cementless porous-coated acetabular component (PFC) following total hip replacement (THR). A total of 287 patients received either a polyethylene acetabular component (group A) or a cobalt-chromium porous-coated component (group B) with an identical cemented femoral component and 28 mm cobalt-chromium head, thus making it the largest study of its type. Patients were evaluated radiologically and clinically using the Harris hip score (HHS). Group A comprised 183 patients (73 male, 110 female) with a mean age of 71.3 years (55 to 89). Group B comprised 104 patients (48 male, 56 female) with a mean age of 69.8 years (56 to 89). A total of 16 patients (13 in Group A, three in Group B) did not have post-operative data for analysis. The mean follow-up in group A was 7.52 years (0.4 to 15.0) and in Group B 7.87 years (0.5 to 14.0). At final follow-up the mean HHS was similar between groups A and B (74.5 (25 to 100) and 78.0 (37 to 100), respectively; p = 0.068). The total number of revisions for any cause was 28, 17 of which were in group A and 11 in group B. The ten-year survivorship was 86.8% (95% confidence interval (CI) 78.4 to 92.1) and 89.2% (95% CI 78.3 to 94.8) for groups A and B, respectively (log-rank p-value = 0.938). A total of 20 cemented and two cementless acetabular components had evidence of acetabular radiolucencies or acetabular component migration at last follow-up (p = 0.001). These results indicate that patients with a cemented all-polyethylene and cementless porous-coated polyethylene lined acetabular component have similar long-term clinical outcomes.

Sciatic nerve injury caused by pre-operative intraneural injection of local anaesthetic during total hip replacement.

We report a case of iatrogenic sciatic nerve injury caused by pre-operative intraneural injection of local anaesthetic at total hip replacement. To our knowledge, this is unreported in the orthopaedic literature. We consider sacral nerve blockade in patients undergoing total hip replacement to be undesirable and present guidelines for the management of peri-operative sciatic nerve injury.

Outcome scoring system evaluation of knee osteoarthritis in patients awaiting TKA.

One hundred and twenty-four patients with knee osteoarthritis were reviewed at three stages over a mean of 24 months (range: 9-32 months) at the time of referral by the general practitioner, by the orthopedic consultant, and before surgery. At each visit, patients were examined and the American Knee Society score and Oxford Knee Society score were obtained. The functional element of the American Knee Score deteriorated significantly from the time of referral until the time of first orthopedic consultation (P=.005) and from the time of referral to the time of surgery (P=.006). The pain element of the American Knee Society score improved from the time of referral till the time of orthopedic assessment (P=.011). The change in Oxford Knee Society score between the time the patient was put on the waiting list to the time of surgery was not statistically significant (P=.30). This article questions the emphasis on surgical waiting times instead of symptoms and physical function in determining timing of surgery.

Bone growth following lengthening for congenital shortening of the lower limb.

Bone and limb growth velocity ratios were studied in patients undergoing lengthening for unilateral congenital shortening of the lower limb. In 15 patients before lengthening, the length ratio (LR) between the normal and short sides remained constant with age. Consequently, the growth velocity ratio (GVR) between the normal and short sides also remained constant and equal to the LR. In 20 children, no significant change in GVR was observed after lengthening was carried out at a mean age of 9.6 years. Our results suggest that final limb length remains reasonably predictable and that an acceptable discrepancy can be expected, especially following lengthening after age 9 years.

The interposition of extensor digitorum brevis in the resection of calcaneonavicular bars.

In this series of 19 resected calcaneonavicular bars for peroneal spastic flatfoot (mean follow-up 3.4 years), we demonstrate that interposition of extensor digitorum brevis led to asymptomatic mobile feet without evidence of recurrence of the bar in 90% of the patients; this compares well with 43% recurrence rates of bars with associated pain and stiffness when extensor digitorum brevis is not interposed. We therefore recommend this method for prevention of the bar and their symptoms.

The Total Condylar III prosthesis in complex knee reconstruction.

Sixty-one Total Condylar III (TC III) prostheses were implanted in 59 patients at the authors' institution between March 1977 and December 1987. Among the knees with adequate clinical and roentgenographic data, the average follow-up period was 6.1 years. There were six primary arthroplasties and 29 revisions in this group. The primary diagnosis was osteoarthrosis in 17 patients, rheumatoid arthritis in 16 patients, and juvenile rheumatoid arthritis in two patients. The knee score improved from 21.9 preoperatively to 73.7 at last follow-up evaluation. Based on the knee score, there were 71% good or excellent results. There were three failures (8.6%). Radiolucent lines were present in at least one component in 71% of patients, but few of these were considered significant. Although rarely needed, the TC III prosthesis has been shown to be a satisfactory and durable solution to complex knee reconstructive problems including severe deformity, ligamentous instability, and bone loss.

Epiphyseal distraction monitored by strain gauges. Results in seven children.

Ten epiphyses in seven children underwent fixed-rate distraction of 0.25 mm twice daily in an attempt to achieve percutaneous leg lengthening by chondrodiatasis. The forces generated across the growth plate were recorded by means of strain gauges incorporated into the distractors. All epiphyses fractured before 33 days of lengthening. An average gain of 6.75 cm was achieved. Epiphyseal distraction at the lower femur produced many complications, but at the upper tibial epiphysis planned lengthening was achieved, with excellent bone production and few complications.

A trial of mezlocillin versus cefuroxime with or without metronidazole for the prevention of wound sepsis after biliary and gastrointestinal surgery.

A randomized controlled trial was undertaken to compare the role of mezlocillin, as the sole prophylactic agent, with a combination of cefuroxime and metronidazole in patients undergoing biliary and gastrointestinal surgery. No difference in wound infection rates was seen in patients following appendicectomy, biliary or gastro-oesophageal surgery. A significantly higher wound infection rate was seen in patients undergoing colorectal surgery who received mezlocillin alone (30.2%) compared with those receiving cefuroxime and metronidazole (11.5%): this rate was similar to that of historical placebo controls in other units. The wound infections seen in patients receiving mezlocillin alone were polymicrobial involving organisms of faecal origin, including non-sporing anaerobes which were predominantly sensitive to mezlocillin. Infections due to Staphylococcus aureus, resistant to mezlocillin, were more frequent in patients receiving mezlocillin and usually secondary in nature. We conclude that mezlocillin may be an effective sole prophylactic agent in appendicectomy but not in colorectal surgery; the possible reasons for failure to adequately prevent infection, following colorectal surgery, are discussed.

Capsular distension and intracapsular pressure in subcapital fractures of the femur.

It has been shown that raised intracapsular pressure causes avascular necrosis of the femoral head in experimental animals, but the relevance of this to clinical fractures of the femoral neck is controversial. We have studied 19 patients with intracapsular fractures of the femoral neck by pressure measurement and by ultrasonography to demonstrate capsular distension. The intra-articular pressure in Garden Grade I and II fractures averaged 66.4 mmHg with a maximum of 145 mmHg. In 10 Garden Grade III and IV fractures the average pressure was 28 mmHg with a maximum of 65 mmHg. Most of the recorded intracapsular pressures were high enough to have caused possible vascular embarrassment, and it is suggested that early decompression of the haemarthrosis should be considered.

Cauda equina and lumbar nerve root compression in patients with AIDS.

Five patients known to be HIV (human immunodeficiency virus)-positive--that is, susceptible to AIDS--presented with symptoms initially thought to be indicative of lumbar disc lesions. Signs of nerve root or cauda equina compression were found in all five patients. Lumbar radiculography and, in one patient, computerised tomography produced no evidence of compressive pathology. We recommend that orthopaedic surgeons exercise caution in diagnosing nerve root compression in patients who may be HIV-positive.