The principle of Occam's razor proves nothing. Nevertheless, it is possible to explain all the phenomena of severe scoliosis on the basis of a primary rotation deformity alone. The typical rotation type of scoliotic deformity can be reproduced artificially by fitting vertebrae together in an abnormal rotatory relationship without any element of lateral flexion. From this, certain mechanical factors inevitably come into play which must tend to increase the deformity. Above all, the forces responsible for progressive scoliosis are dynamic and active, not just passive. The spine readily compensates for a passive, non-progressive deformity such as a simple wedge vertebra. It is my belief that rotation is usually the dominant factor and that correction and control of severe scoliosis can only be achieved by concentrating on the rotation deformity. I am well aware that this is an old idea but its essential truth has been insufficiently appreciated in recent years and we have not faced its full implications. Failure to correct rotation invites recurrence. Conversely, even a slight reduction in rotation usually produces a marked cosmetic improvement, often out of all proportion to the radiographic appearances

Arthroplasty, with normal or nearly normal reposition, is possible in most old congenital dislocations of the hip in young adults. Reposition is possible even in very high dislocation, but it is difficult or impossible in aged patients and when arthritic changes have taken place. The reduction equalises the length of the extremities in unilateral cases, but makes operation on both sides necessary in bilateral cases. Post-operative complications may be largely avoided by a good technique and careful post-operative treatment. Stability is good, and consequently the limp is generally reduced. Mobility is as a rule sufficient, though often less than before operation when the hip was normally or excessively mobile. Pain is very often relieved or greatly reduced, but walking is generally limited. Even if the radiographic appearance of the hip is almost normal, the functional result may be imperfect. This assessment is probably pessimistic, for two reasons: first, patients operated on are still improving; second, the improved technique of the later operations should give better results. Nevertheless, arthroplasty with reduction should be proposed to patients only suffering severe functional disability

We describe the clinical and radiological results of 120 consecutive revision hip replacements in 107 patients, using the JRI Furlong hydroxyapatite-ceramic-coated femoral component. The mean age of the patients at operation was 71 years (36 to 92) and the mean length of follow-up 8.0 years (5.0 to 12.4). We included patients on whom previous revision hip surgery had taken place. The patients were independently reviewed and scored using the Harris hip score, the Western Ontario and McMaster Universities osteoarthritis index (WOMAC) and the Charnley modification of the Merle d’Aubigné and Postel score. Radiographs were assessed by three reviewers for the formation of new bone, osteolysis, osseointegration and radiolucent lines in each Gruen zone. The mean Harris hip score was 85.8 (42 to 100) at the latest post-operative review. The mean WOMAC and Merle d’Aubigné and Postel scores were 34.5 and 14.8, respectively. The mean visual analogue score for pain (possible range 0 to 10) was 1.2 overall, but 0.5 specifically for mid-thigh pain. There were no revisions of the femoral component for aseptic loosening. There were four re-revisions, three for infection and one for recurrent dislocation. Radiological review of all the femoral components, including the four re-revisions showed stable bony ingrowth and no new radiolucent lines in any zone. Using revision or impending revision for aseptic loosening as an end-point, the cumulative survival of the femoral component at ten years was 100% (95% confidence interval 94 to 100). We present excellent medium- to long-term clinical, radiological and survivorship results with the fully hydroxyapatite-ceramic-coated femoral component in revision hip surgery

We have followed the natural progress of newborn infants in whom ultrasound examination showed abnormalities in hips which appeared to be clinically normal. Over six years we saw 306 such children out of 9952 examined (31 per 1000 live births). The examination was repeated at two to three months and those who still showed an abnormality were followed up further. At four to five months a standard radiograph was obtained, and treatment began if this and another ultrasound scan were both abnormal. At this stage, 291 infants had normal hips. In the 15 infants with abnormal hips there was no pronounced deterioration, none developed a frank dislocation, and all became normal after treatment in an abduction splint. Newborn infants with abnormal and suspicious ultrasound findings who are normal on clinical examination do not need treatment from birth; most of these hips will settle spontaneously. Treatment can be postponed until the age of four to five months unless clinical instability develops or ultrasound shows dislocation. The criteria for treatment should be based on measurements by both ultrasound and radiography: both should show an abnormality before intervention is considered necessary

We report a prospective, stratified study of 60 PCA-cups and 60 RM-polyethylene cups which have been followed for a median time of 90 months, with annual radiography. The radiological migration of cups was measured by the computer-assisted EBRA method. A number of threshold migration rates from 1 mm in the first year to 1 mm in five years have been assessed and related to clinically determined revision rates. A total of 28 cups showed a total migration of 1 mm or more within the first two years; 13 of these cups have required revision and been exchanged. The survival curves of cups which had previously shown early migration were considerably different from those without early migration. For cups with a migration of less than 1 mm within the first two years the mean survival at 96 months was 0.96 ± 0.02; for migrating cups, it was 0.63 ± 0.11 (log-rank test, p = 0.0001; chi-square value = 39.4). Early migration is a good predictor for late loosening of hip sockets

We report the incidence of osteolysis in the femur, tibia, and patella of 44 consecutive patients (60 knees) who were followed for more than seven years after cementless knee arthroplasty with a Porous-Coated Anatomic prosthesis. The average age of the patients was 56.5 years (17 to 73); the operative diagnosis was osteoarthritis (33 knees), rheumatoid arthritis (17), tuberculous arthritis (7) and post-traumatic arthritis (3). All patellae were resurfaced. No femoral or tibial component was loose at the final follow-up examination. Thirty patellar components were loose of which six had been revised. Radiographs revealed osteolysis in 90% of the tibial plateaux and in 80% of the 30 intact patellar prostheses. No osteolysis was seen around any femoral component. In 50 knees (83%) the average wear of the polyethylene liner was 2.5 mm in the medial compartment and 1.7 mm in the lateral compartment. Four of 60 knees (6.7%) were revised for complete wear of the polyethylene liner of the tibial component. Fixation of the tibial and patellar components without cement fails to seal the interface between bone and prosthesis and allows the migration of polyethylene particulate debris which causes osteolysis

We performed a prospective study to assess the long-term outcome of 57 arthroscopic debridement procedures carried out to treat anterior impingement in the ankle. Using preoperative radiographs, we grouped patients according to the extent of their osteoarthritis (OA). The symptoms of those with grade-0 changes could be attributed to anterior soft-tissue impingement alone. Patients with grade-I disease had both anterior soft-tissue and osteophytic impingement, but no narrowing of the joint space. In those with grade-II OA, narrowing of the joint space was accompanied by osteophytic impingement. Radiographs taken before and after operation and at follow-up were compared to assess the recurrence of osteophytes and the progression of narrowing of the joint space. At a mean follow-up of 6.5 years (5 to 8) all patients without OA had excellent or good results. There were excellent or good results in 77% of patients with grade-I OA, despite partial or complete recurrence of osteophytes in two-thirds. In most patients with grade-II OA, narrowing of the joint space had not progressed at follow-up. There was a notable improvement in pain in these patients, 53% of whom had excellent or good results. Although some osteophytes recurred, at long-term follow-up arthroscopic excision of soft-tissue overgrowths and osteophytes proved to be an effective way of treating anterior impingement of the ankle in patients who had no narrowing of the joint space

We reviewed the results of 13 adults of secondary reconstruction of malunited and ununited intraarticular distal humeral fractures. Their average age was 39.7 years, and preoperatively all had pain, loss of motion and functional disability; the average arc of motion was only 43 degrees and the average flexion contracture was 45 degrees. Nine patients had ulnar neuropathy. Elbow reconstruction, at an average of 13.4 months after the original injury, included osteotomy for malunion or debridement for nonunion, realignment with stable fixation and autogenous bone grafts, anterior and posterior capsulectomy and ulnar neurolysis. The elbows were mobilised 24 hours postoperatively. There were no early complications and all nonunions and intra-articular osteotomies healed. After a mean follow-up of 25 months, the average arc of motion was 97 degrees with no progressive radiographic degeneration. Ulnar nerve function improved in all cases and clinical assessment using the Morrey score showed two excellent, eight good and three fair results. Reconstruction of intra-articular malunion and nonunion of the distal humerus in young active adults is technically challenging, but can improve function by restoring the intrinsic anatomy of the elbow

We examined radiographic polyethylene wear in 233 cemented total hip arthroplasties (201 patients) with either a metal-backed or a non-metal-backed acetabular cup. All patients had identical cemented one-piece titanium femoral stems with a femoral head diameter of 28 mm. The mean linear wear rate was 0.11 mm/yr in metal-backed sockets and 0.08 mm/yr in non-metal-backed sockets (p = 0.0002). The mean volumetric wear rate was 66.2 mm3/yr in the metal-backed sockets and 48.2 mm3/yr in the polyethylene sockets (p = 0.0002). The addition of metal backing to a cemented acetabular cup therefore resulted in a 37% increase in mean polyethylene wear rates which may partially explain the higher failure rate of cemented metal-backed cups. Linear regression analysis also implicated increased follow-up time (log), gross acetabular migration, metal backing and male gender in increasing polyethylene wear. We advocate the use of an all-polyethylene cup in cemented total hip arthroplasty. The increased polyethylene wear must also cause concern about the wear rate of uncemented metal-backed acetabular sockets

Fractures of the hip in children have been associated with a very high rate of serious complications including avascular necrosis (up to 47%) and coxa vara (up to 32%). Over a period of 20 years, we have treated displaced fractures by early anatomical reduction, internal fixation and immobilisation in a spica cast to try to reduce these complications. We have reviewed 18 patients who had a displaced non-pathological fracture of the hip when under 16 years of age. Their mean age at the time of the injury was eight years (2 to 13). They returned for examination and radiography at a mean follow-up of eight years (2 to 17). Each patient had been treated by early (″24 hours) closed or open reduction with internal fixation and 16 had immobilisation in a spica cast. By Delbet’s classification, there was one type-I, eight type-II, eight type-III, and one type-IV fractures. There were no complications in 15 patients. Avascular necrosis occurred in one patient (type-III), nonunion in one (type-II, one of the two patients who did not have a cast) and premature physeal closure in one (type-I). There were no cases of infection or complications as a result of the cast. Our treatment of displaced hip fractures in children by early reduction, internal fixation, and immobilisation in a spica cast gave reduced rates of complications compared with that of large published series in the literature

Aims

The aim of this study was to compare early functional and health related quality of life outcomes (HRQoL) in patients who have undergone total hip arthroplasty (THA) using a bone conserving short stem femoral component and those in whom a conventional length uncemented component was used. Outcome was assessed using a validated performance based outcome instrument as well as patient reported outcome measures (PROMs).

Objectives

Preservation of posterior condylar offset (PCO) has been shown to correlate with improved functional results after primary total knee arthroplasty (TKA). Whether this is also the case for revision TKA, remains unknown. The aim of this study was to assess the independent effect of PCO on early functional outcome after revision TKA.

We evaluated 38 hip reconstructions in 36 patients at a mean follow-up of 5.9 years (range 4 to 9.1) after femoral head allografts had been used to augment severely deficient acetabular bone stock. The patients were all relatively young and had many previous operations. Their pre-operative Harris hip rating averaged 46 points (range 18 to 73). All the allografts united and there were no infections. However, 12 acetabular components (32%) became loose; six of these had needed revision using the healed allograft, and two hips had required resection arthroplasty. The 30 surviving hips had a mean Harris hip score of 82 points. Some radiographic evidence of graft resorption was seen in 23 hips, though this was mild in 17. The extent of cover provided by the allograft and the severity of graft resorption both correlated with acetabular loosening. Although structural allografts had allowed successful hip reconstructions in many of these patients with major bone loss, the failure rate had increased from zero at four years to 32% at six years; clearly they provide only a short-term solution

The histology and mechanics of leg lengthening by callus distraction were studied in 27 growing rabbits. Tibial diaphyses were subjected to subperiosteal osteotomy, held in a neutral position for 10 days and then slowly distracted at 0.25 mm/12 hours, using a dynamic external fixator. Radiographs showed that the gap became filled with callus having three distinct zones. Elongation appeared to occur in a central radiolucent zone; this was bounded by two sclerotic zones. Histologically, the radiolucent zone consisted of longitudinally arranged cartilage and fibrous tissue while the sclerotic zones were formed by fine cancellous bone. New bone occasionally contained islands of cartilage, suggesting it had been formed by endochondral ossification. After completion of distraction, the two sclerotic zones fused, shrank and were eventually absorbed, leaving tubular bone with a new cortex. When the periosteum had been removed at the operation, callus formation was markedly disturbed and there was failure of bone lengthening. Scraping of endosteum, in contrast, did not have a pronounced effect. These results suggest that the preservation of periosteum is essential if bone lengthening by callus distraction is to succeed, and that preservation of the periosteum is more important than careful corticotomy

Objectives

Static radiostereometric analysis (RSA) using implanted markers is considered the most accurate system for the evaluation of prosthesis migration. By using CT bone models instead of markers, combined with a dynamic RSA system, a non-invasive measurement of joint movement is enabled. This method is more accurate than current 3D skin marker-based tracking systems. The purpose of this study was to evaluate the accuracy of the CT model method for measuring knee joint kinematics in static and dynamic RSA using the marker method as the benchmark.

Most patients with dominantly inherited osteogenesis imperfecta have blue sclerae and relatively mild symptoms. However, in a small group of families the patients have normal sclerae and this disorder has been classified as Type 4 osteogenesis imperfecta. This paper reports the clinical and radiographical features of 48 patients from 16 families with Type 4 osteogenesis imperfecta and compares the findings with those of the classical disorder with blue sclerae (Type 1 osteogenesis imperfecta). The two types are similar in usually causing a mild disease but with a wide range of severity, and in both types the rate of fracture declines in adolescence. There are, however, some significant differences apart from the colour of the sclerae. In Type 4 the first fracture more commonly occurs at birth, dentinogenesis imperfecta is more frequent than in Type 1 and bruising and nose-bleeds are less common. As in Type 1, the radiographic appearances of the bones may be normal. It is important that Type 4 osteogenesis imperfecta should be recognised because of the need for competent genetic counselling, because the management may be different from that appropriate for Type 1 and because it may be mistaken for idiopathic juvenile osteoporosis or child abuse

The division of osteoarthritis into primary and secondary varieties implies that these are aetiologically distinct entities, the former being due to some intrinsic defect of cartilage and the latter resulting from previous articular damage. This traditional concept is questioned and the hypothesis is advanced that osteoarthritis is always secondary to some underlying abnormality of the joint. A detailed clinical, radiographic and morbid anatomical study of 327 cases of osteoarthritis of the hip is presented. In all but twenty-seven some predisposing abnormality of the joint was diagnosed: 107 (33%) were associated with major pathology such as Perthes' disease or epiphysiolysis; minor acetabular dysplasia was present in sixty-seven (20%), with a male: female ratio of 1:10; minimal femoral head tilt was demonstrated in fifty-nine (18%), the male: female ratio being 14:1; and in forty-three (13%) there were features suggesting an underlying inflammatory arthritis. On the basis of this study a new classification is proposed and osteoarthritis of the hip is divided into three pathogenetic groups: 1) failure of essentially normal cartilage subjected to abnormal or incongruous loading for long periods; 2) damaged or defective cartilage failing under normal conditions of loading; 3) break-up of articular cartilage due to defective subchondral bone

1. Radiography of the spines of thirty-three West African patients recently recovered or dead from tetanus revealed vertebral fractures in nineteen. These fractures occurred most frequently in the fourth to eighth thoracic vertebrae. 2. The spines of 111 Nigerians from the same area of West Africa were examined, measurement of the areas and shape of the vertebral bodies carried out, and the proportional incidence of articular shelves and laminar spicules was calculated. 3. The upper mid-thoracic vertebral bodies are relatively long and narrow and have but little greater cross-sectional area than those immediately above them; possessing no neural arch supports to sustain longitudinal compressive forces in flexion, they are at greatest hazard during tetanic spasms. 4. Analyses of these factors and of the clinical features, together with experimental observations drawn from the literature, are used to explain the prevalence of upper mid-thoracic vertebral fractures as a complication of tetanus in West Africans, and in particular the greater degree of compression and higher incidence found in children. 5. Vertebral fracture is not usually an important complication of tetanus; it causes little pain, does not prolong the illness, gives rise to no permanent disability and has no effect on the mortality

1. Clinically, hallux rigidus is a painful condition of the joints of the great toe associated with loss of dorsiflexion of the first phalanx. 2. Pathologically, the morbid changes are those of a traumatic synovitis followed by an early development of osteoarthritis, the initial lesions of which are erosions of the cartilage at the centre and near the dorsal margin of the base of the proximal phalanx. There is no fundamental pathological difference between the adult and adolescent varieties of hallux ngidus. Both represent stages in the developmental cycle of osteoarthritis in the proximal joint of the great toe. 3. The radiographic density and apparent fragmentation of the phalangeal epiphysis do not represent an abnormality of the bone and have no significance in the etiology of hallux rigidus. 4. The cause of hallux rigidus is an abnormal gait developed either to protect an injured or inflamed metatarso-phalangeal joint from the pressure of weight-bearing, or to stabilise a hypermobile first metatarsal. The effects of this gait are to transfer most of the pressure from the flexor brevis tendon and the two sesamoids to the base of the first phalanx. Excessive pressure on this joint predisposes to osteoarthritis. 5. Evidence of this abnormal gait is found in the peculiarities of wear seen in old shoes. 6. There is a high correlation between unilateral hallux rigidus and the patient's footedness

We assessed the intermediate functional results of eight patients after wide resection of the proximal humerus for malignant bone tumour. We used a free vascularised fibular graft as a functional spacer and a sling procedure to preserve passive scapulohumeral movement. Scapulohumeral arthrodesis was not carried out. Five patients had osteosarcoma, two achondrosarcoma and one a malignant fibrous histiocytoma of the bone. The mean duration of follow-up was 70 months (median, 76) for the seven patients who were still alive at the time of the latest follow-up. One patient died from the disease 12 months after surgery. There were no local recurrences. The functional results were described and graded quantitatively according to the rating system of the Musculoskeletal Tumour Society. Our results were satisfactory with regard to pain, emotional acceptance and manual dexterity. Function and lifting ability were unsatisfactory in two patients. One patient had delayed union between host and graft, but this united after six months without further surgery. Radiographs of the shoulder showed absorption or collapse of the head of the fibula in four of the eight patients and a fracture in another. No functional problems related to absorption or fracture of the head of the fibula were noted. There was no infection or subluxation of the head. We conclude that this is a reasonably effective technique of limb salvage after resection of the proximal humerus