We have assessed the effectiveness of reconstruction of the anterior cruciate ligament (ACL) in reducing functional tibial translation (TT).

The gait of 11 ACL-deficient patients was studied using Vicon equipment before and after surgery. Measurements of the angle between the patellar tendon and the long axis of the tibia were obtained in order to calculate TT in the sagittal plane relative to the uninjured limb during standing and walking.

Before surgery, patients did not show abnormal TT on the injured side, but after surgery significant anterior TT was found in the operated limb for every parameter of gait.

Abnormal anterior TT occurring during activity does not seem to be reduced by reconstruction; rather, it increases. It may be that the increased translation results from relaxation of excess contraction of the hamstring muscles, since compensatory muscle activity no longer is required in a reconstructed knee. The reduction of TT may not be an appropriate objective in surgery on the ACL.

Surgical dislocation of the hip is rarely undertaken. The potential danger to the vascularity of the femoral head has been emphasised, but there is little information as to how this danger can be avoided. We describe a technique for operative dislocation of the hip, based on detailed anatomical studies of the blood supply. It combines aspects of approaches which have been reported previously and consists of an anterior dislocation through a posterior approach with a ‘trochanteric flip’ osteotomy. The external rotator muscles are not divided and the medial femoral circumflex artery is protected by the intact obturator externus. We report our experience using this approach in 213 hips over a period of seven years and include 19 patients who underwent simultaneous intertrochanteric osteotomy. The perfusion of the femoral head was verified intraoperatively and, to date, none has subsequently developed avascular necrosis. There is little morbidity associated with the technique and it allows the treatment of a variety of conditions, which may not respond well to other methods including arthroscopy. Surgical dislocation gives new insight into the pathogenesis of some hip disorders and the possibility of preserving the hip with techniques such as transplantation of cartilage.

We analysed the long-term results with a mean follow-up of 10.2 years, of 66 total knee replacements in 42 patients with rheumatoid arthritis. In all cases the posterior cruciate ligament was retained.

There were only three complications (4.5%). Revision surgery was necessary in five knees (7.6%), including one (1.5%) with infection. At the final follow-up, 75.8% of knees were rated excellent clinically. Only 15% had an excellent function score. The survival rate of the implant was 90.7% at 19 years.

The clinical, radiological and survivorship analysis shows that the posterior-cruciate-retaining knee arthroplasty performs well in rheumatoid arthritis.

We present the long-term results of the Kinematic Condylar Knee Arthroplasty followed in a prospective fashion. Between October 1982 and March 1988, 404 consecutive replacement arthroplasties were carried out on 335 patients. Of these, 354 knees had osteoarthritis, 45 rheumatoid arthritis and five other diagnoses. At the time of final follow-up 158 patients (188 knees) had died. No patient was lost to follow-up. The minimum follow-up for all living patients was ten years (10 to 17). The mean age at surgery was 68 years (30 to 92). There were seven complications (1.7%). Sixteen knees (3.9%) were revised, four because of infection. Survivorship was 99.4% (CI 97.9 to 99.8) at five years, 98.2% (CI 96.1 to 99.2) at ten years and 92.6% (CI 87.6 to 95.6) at 17 years.

The primary source for the blood supply of the head of the femur is the deep branch of the medial femoral circumflex artery (MFCA). In posterior approaches to the hip and pelvis the short external rotators are often divided. This can damage the deep branch and interfere with perfusion of the head.

We describe the anatomy of the MFCA and its branches based on dissections of 24 cadaver hips after injection of neoprene-latex into the femoral or internal iliac arteries.

The course of the deep branch of the MFCA was constant in its extracapsular segment. In all cases there was a trochanteric branch at the proximal border of quadratus femoris spreading on to the lateral aspect of the greater trochanter. This branch marks the level of the tendon of obturator externus, which is crossed posteriorly by the deep branch of the MFCA. As the deep branch travels superiorly, it crosses anterior to the conjoint tendon of gemellus inferior, obturator internus and gemellus superior. It then perforates the joint capsule at the level of gemellus superior. In its intracapsular segment it runs along the posterosuperior aspect of the neck of the femur dividing into two to four subsynovial retinacular vessels. We demonstrated that obturator externus protected the deep branch of the MFCA from being disrupted or stretched during dislocation of the hip in any direction after serial release of all other soft-tissue attachments of the proximal femur, including a complete circumferential capsulotomy.

Precise knowledge of the extracapsular anatomy of the MFCA and its surrounding structures will help to avoid iatrogenic avascular necrosis of the head of the femur in reconstructive surgery of the hip and fixation of acetabular fractures through the posterior approach.

Studies using roentgen stereophotogrammetric analysis (RSA) have shown that the femoral components of cemented total hip replacements (THR) migrate distally relative to the bone, but it is not clear whether this occurs at the cement-implant or the cement-bone interface or within the cement mantle. Our aim was to determine where this migration occurred, since this has important implications for the way in which implants function and fail.

Using RSA we compared for two years the migration of the tip of the stem with that of the cement restrictor for two different designs of THR, the Exeter and Charnley Elite. We have assumed that if the cement restrictor migrates, then at least part of the cement mantle also migrates.

Our results have shown that the Exeter migrates distally three times faster than the Charnley Elite and at different interfaces. With the Exeter migration was at the cement-implant interface whereas with the Charnley Elite there was migration at both the cement-bone and the cement-implant interfaces.

Patients who had a revision total hip arthroplasty using the Bürch-Schneider anti-protrusio cage (APC) by a single surgeon have been reviewed after a minimum of five years. There were 63 operations in 58 patients with an average age of 63 years (41 to 83) at the time of revision. At an average follow-up of 8.5 years (5 to 18), 15 patients (25.9%) rated their results as excellent, 38 (65.5%) as good, and five (8.6%) as fair. Five further revisions of the acetabular prosthesis were required, three due to aseptic loosening, one for recurrent dislocation and one due to sepsis. Of the remainder, one was definitely loose, two probably loose, and 12 possibly so.

Impressive augmentation of bone stock can be achieved with the anti-protrusio cage, while enabling the hip to be centred in its anatomical position.

We reviewed 26 consecutive men of mean age 28 years who had had wedge bone grafting and Herbert screw fixation for symptomatic established nonunion of the waist of the scaphoid. The period between injury and operation averaged 30 months (10 to 96), and 11 of the 26 patients had had previous operations, seven with bone grafts.

At a mean follow-up of 14 months (6 to 42) 25 fractures (95%) had united at a median time of four months. Symptoms were improved in all patients. The outcome was not related to the time between injury and surgery or to pre-existing degenerative changes. Previous surgery carried a worse prognosis.

The technique is difficult but can achieve union even when previous surgery and bone grafting have failed. The usual result is improved function and some relief of pain.