1. The semilunar cartilages are part of the rotator mechanism of the knee joint. 2. Movement of the weight-bearing knee comprises synchronous lateral rotation of the tibia with extension and medial rotation of the tibia with flexion. 3. When this synchrony is disturbed, injuries to the semilunar cartilages result. 4. Damage to the anterior two-thirds of the medial cartilage blocks lateral rotation of the tibia, with consequent physical signs that are pathognomonic of the retracted and the bowstring cartilage, which are the most common types of injury. 5. Each type of cartilage injury produces its own pattern of erosion of articular cartilage and its own sequence of symptoms as so-called arthritis develops. 6. The sequence of symptoms may be halted and often reversed by removal of the torn cartilage. Operation is warranted in most cases however long the history and whatever the age of the patient. 7. The development of medial retropatellar arthritis is explained. The symptoms are often relieved by removal of the medial semilunar cartilage and adequate post-operative rehabilitation

After a severe ankle sprain the incidence of residual complaints, particularly on the medial side of the joint, is high. We studied a consecutive series of 30 patients who had operative repair of acute ruptures of lateral ligaments. During operation, arthroscopy revealed a fresh injury to the articular cartilage in 20 ankles, in 19 at the tip and/or anterior distal part of the medial malleolus as well as on the opposite medial facet of the talus. In six patients, a loose piece of articular cartilage was found. We conclude that in patients with a rupture of one or more of the lateral ankle ligaments after an inversion injury, an impingement occurs between the medial malleolus and the medial facet of the talus. Patients with a lesion of the lateral ankle ligament caused by a high-velocity injury (a faulty landing during jumping or running) had a higher incidence of macroscopic cartilage damage (p < 0.01), medially-located pressure pain (p = 0.06) and medially-located complaints at one-year follow-up (p = 0.02) than those with a low-velocity injury (a stumble)

We have previously shown that prior exposure of rat hind limbs to ischaemia for five minutes and reperfusion for five minutes reduced the structural damage to skeletal muscle which followed a subsequent period of ischaemia for four hours and reperfusion for one hour. We have now examined the potential mechanisms by which this ischaemic preconditioning protocol may be effective in reducing damage to skeletal muscle induced by prolonged ischaemia and reperfusion. Prior exposure of the hindlimb to ischaemia for five minutes and reperfusion for five minutes did not prevent the fall in the ATP content of tibialis anterior which occurred after a subsequent period of ischaemia for four hours and reperfusion for one hour. Similarly, no effect of the preconditioning protocol was seen on the elevated muscle myeloperoxidase, indicative of an elevated neutrophil content, or abnormal muscle cation content. Reperfused ischaemic muscle was also found to have an increased content of heat-shock protein (HSP) 72, but the preconditioning protocol did not further increase the content of this or other HSPs indicating that it was not acting by increasing the expression of these cytoprotective proteins. The protective effects of preconditioning appeared to be mimicked by the infusion of adenosine to animals immediately before exposure to the four-hour period, indicating a potential mechanism by which skeletal muscle may be preconditioned to maintain structural viability

Aims

Open reduction is required following failed conservative treatment of developmental dysplasia of the hip (DDH). The Ludloff medial approach is commonly used, but poor results have been reported, with rates of the development of avascular necrosis (AVN) varying between 8% and 54%. This retrospective cohort study evaluates the long-term radiographic and clinical outcome of dislocated hips treated using this approach.

We have studied, prospectively, 116 patients with motor deficits associated with herniation of a lumbar disc who underwent microdiscectomy. They were studied during the first six months and at a mean of 6.4 years after surgery. Before operation, muscle weakness was mild (grade 4) in 67% of patients, severe (grade 3) in 21% and very severe (grade 2 or 1) in 12%. The muscle which most frequently had severe or very severe weakness was extensor hallucis longus, followed in order by triceps surae, extensor digitorum communis, tibialis anterior, and others. At the latest follow-up examination, 76% of patients had complete recovery of strength. Persistent weakness was found in 16% of patients who had had a mild preoperative deficit and in 39% of those with severe or very severe weakness. Muscle strength was graded 4 in all patients with persistent weakness, except for four with a very severe preoperative deficit affecting the L5 or S1 nerve root. They showed no significant recovery. Excluding this last group, the degree of recovery of motor function was inversely related to the preoperative severity and duration of muscle weakness. The patients’ subjective functional capacity was not directly related to the degree of recovery except in those with persistent severe or very severe deficit

We carried out a cadaver study of 16 iliolumbar veins in order to define the surgical anatomy. Two variants were found; a single vein at a mean distance of 3.74 cm from the inferior vena cava (11 of 16) and two separate draining veins at a mean distance from the vena cava of 2.98 cm for the proximal and 6.24 cm for the distal stem (5 of 16). Consistently, the proximal vein tore on attempted medial retraction of the great vessels. The mean length of the vein was 1.6 cm and its mean width 1.07 cm. Three stems were shorter than 0.5 cm. Two or more tributaries usually drained the iliacus and psoas muscles, and the fifth lumbar vertebral body. The obturator nerve crossed all veins superficially at a mean of 2.76 cm lateral to the mouth. In four of these, this distance was less than 1.5 cm. Usually, the lumbosacral trunk crossed deep, at a mean distance of 2.5 cm lateral to the mouth, but in three veins, this distance was 1 cm or less. Our findings emphasise the need for proper dissection of the iliolumbar vein before ligature during exposure of the anterior lumbar spine

We performed CT to investigate how treatment may modify the basic skeletal pathology of congenital club foot. Two homogenous groups of patients treated by one of the authors (EI) or under his supervision were studied. The first included 32 patients with 47 club feet reviewed at a mean age of 25 years and treated by manipulation, application of toe-to-groin plaster casts and an extensive posteromedial release. The second included 32 patients with 49 club feet reviewed at a mean age of 19 years and treated by the Ponseti manipulation technique, application of toe-to-groin plaster casts and a limited posterior release. At follow-up the shape of the subtalar, talonavicular and calcaneocuboid joints was found to be altered in many feet in both groups. This did not appear to be influenced significantly by the type of treatment performed. Correction of the heel varus and the increased declination angle of the neck of the talus was better in the club feet of the second group, whereas reduction of the medial subluxation of the navicular was better in the first. There was a marked increase in the external ankle torsion angle in the first group and a moderate increase of this angle in the second group, in which medial subluxation of the cuboid on the anterior apophysis of the calcaneum was always corrected. Equinus was corrected in both groups but three-dimensional CT reconstruction of the whole foot showed that cavus, supination and adduction deformities were corrected much better in the second group

Sixty-nine hips in 62 patients were treated by the Pavlik harness for congenital dislocation. Ultrasonography showed three degrees of residual head displacement when the harness was first applied. In type A, the femoral head showed contact with the inner posterior wall of the acetabulum. In type B, it contacted the posterior margin of the socket, with its centre at or anterior to the acetabular rim. In type C, the femoral head was displaced outside the socket, with its centre posterior to the acetabular rim. All 51 hips with type A displacement remained reduced. Of nine hips of type B, five were reduced, but the other four were not. None of the nine hips with type C dislocation became reduced with continued use of the harness. The Pavlik harness is indicated for type A and some type B dislocations, but the latter need daily ultrasound monitoring, with a change in method of treatment if type C displacement appears or if the hip is not reduced within one or two weeks. Treatment by Pavlik harness is not indicated in hips with type C dislocations

Fifty-five patients with severe pain from spinal instability secondary to metastatic cancer were referred to Hope Hospital, none being judged to be in a terminal condition. One patient had too extensive disease for surgery so 54 were treated by 55 spinal stabilisations; 49 obtained complete relief of pain and two had partial relief. There were three failures. Twenty-eight of the patients had clinical evidence of spinal cord or cauda equina compression and were decompressed at the time of stabilisation. Of these, 20 had major recovery of neurological function. Patients with pre-operative evidence of extradural tumour had 'prophylactic' decompression at the time of stabilisation; none of these patients later developed signs of cord or cauda equina compression. The results suggest that alleviation of pain and restoration of mobility are best achieved by segmental spinal stabilisation; a few patients require a combined anterior and posterior stabilisation. Postoperative radiotherapy should be given whenever possible, and the causative tumour should be treated by endocrine or chemotherapy, as indicated

Nine patients underwent arthrodesis of the knee using a customised coupled nail (the Mayday arthrodesis nail), five after infected arthroplasty, one following failed arthrodesis, one for intractable anterior knee pain, one for Charcot instability and one after trauma. Comparison was made with 17 arthrodeses, eight undertaken using external fixation, four with dual compression plates, and five with long Küntscher nails. Union was achieved in all patients (100%) at a mean time of ten months using the customised implant. There were no complications despite early weight-bearing. No further procedures were required. This contrasted with a rate of union of 53% and a complication rate of 76% with alternative techniques. Of this second group, 76% required a further operative procedure. We compared the Mayday arthrodesis nail with other techniques of arthrodesis of the knee. The differences in the need for further surgery and occurrence of complications were statistically significant (p < 0.001), and differences in the rate of nonunion and inpatient stay of less than three weeks were also significant (p < 0.05) using Fisher’s exact test. We conclude that a customised coupled intramedullary nail can give excellent stability allowing early weight-bearing, and results in a high rate of union with minimal postoperative complications

From the experimental evidence above, it is clear that in the upper four centimetres of the forearm the posterior interosseous nerve moves up to one centimetre or more medially relative to the radius on pronation of the forearm. This movement becomes of importance when considered in relation to methods of operative approach for excision of the radial head. Operative approaches have been described in which emphasis has been placed on the position of incision, but in none of these is there any mention of the position of the forearm. We suggest that the following precautions should be taken. 1) During excision of the radial head the forearm should be kept in full pronation. 2) The incision should be as posterior as possible to ensure that it is well clear of the nerve. 3) With the forearm pronated the incision extends from a little above the lateral epicondyle along the postero-lateral aspect of the forearm for not more than 5 centimetres; proportionately less in a child. 4) The surgical assistant's attention should be brought to the damage that the posterior interosseous nerve might sustain from undue pressure–for instance by retraction, especially by bone levers–in the anterior part of the wound

1. The strength of the pelvic arch depends on the integrity of the anterior interpubic ligament, whose strength has been demonstrated by dissections. Once that ligament is divided the sacro-iliac ligaments offer little resistance to opening out of the pelvis. 2. The structure of the pelvis and hips is compared to an arcade formed by a central and two lateral arches. The weight of the trunk is transmitted to the lower limbs through this arcade. 3. Fractures of the pelvis are classified according to the mechanism of production. The case for anatomical reposition and internal fixation is stated, and case histories are given to illustrate the disabilities due to persistent deformity. 4. Reduction can be achieved as late as two or three weeks after injury. However, if early operation for visceral injury is necessary, there is a strong case for combining this with open reduction and fixation. In some cases the patient's general condition may preclude such procedures, but more usually the additional manipulations cause little additional operative shock and are fully justified by the subsequent increased comfort of the patient and the greater ease of nursing

We analysed the incidence of avascular necrosis in 101 hips of 90 infants with congenital dislocation treated with the Pavlik harness and followed up for more than one year. Using ultrasonography in the flexed-abducted position the hips were classified as type A when the femoral head was displaced posteriorly, but within the socket and making contact with the posterior inner wall of the acetabulum; type B when it was in contact with the posterior margin of the acetabulum, with its centre at this level or anterior to it; and type C when it was displaced out of the socket, with its centre posterior to the posterior rim of the acetabulum. Eighty-seven hips were reduced by the harness (86%), and seven of these developed avascular necrosis (8%). All 69 hips with type-A dislocation were reduced, and only one (1.4%) showed slight avascular necrosis. Eighteen (78.3%) of 23 hips with type-B dislocation were reduced, and six developed avascular necrosis (33.3%). In one hip, the femoral head was severely damaged. None of the nine hips with type-C dislocation was reduced in the harness. We conclude that the Pavlik harness is indicated for type-A, but not for type-B or type-C dislocations

We have compared the changes in the pattern of the principal strains in the proximal femur after insertion of eight uncemented anatomical stems and eight customised stems in human cadaver femora. During testing we aimed to reproduce the physiological loads on the proximal femur and to simulate single-leg stance and stair-climbing. The strains in the intact femora were measured and there were no significant differences in principal tensile and compressive strains in the left and right femora of each pair. The two types of femoral stem were then inserted randomly into the left or right femora and the cortical strains were again measured. Both induced significant stress shielding in the proximal part of the metaphysis, but the deviation from the physiological strains was most pronounced after insertion of the anatomical stems. The principal compressive strain at the calcar was reduced by 90% for the anatomical stems and 67% for the customised stems. Medially, at the level of the lesser trochanter, the corresponding figures were 59% and 21%. The anatomical stems induced more stress concentration on the anterior aspect of the femur than did the customised stems. They also increased the hoop strains in the proximomedial femur. Our study shows a consistently more physiological pattern of strain in the proximal femur after insertion of customised stems compared with standard, anatomical stems

We reviewed 26 patients with 34 shoulders treated by the inferior capsular shift operation for inferior and multidirectional instability. The mean follow-up was 8.3 years. In total, 12 shoulders showed voluntary subluxation. Eight operations used an anterior and posterior approach, 11 were by the posterior route, and 15 shoulders had an anterior approach. In 30 shoulders (85%) the outcome was satisfactory and 20 (59%) scored good or excellent results on the Rowe system. Instability had recurred in nine shoulders (26%) from three months to three years after the operation. Six of the 12 shoulders with voluntary subluxation (50%) had recurrence, as against three of the other 22 (14%), a statistically significant difference. The operation is therefore not indicated for voluntary subluxation. The 19 shoulders which had been assessed in 1987 at a mean of 3.5 years after surgery, were also reviewed in 1995 and found to have no significant changes in instability or Rowe score. This shows that the capsular shift appeared to have maintained its tension over an eight-year period. After the use of a posterior approach, 64% of the shoulders showed a posterolateral defect on radiographs of the humerus

Anterior knee pain due to dysplasia of the extensor mechanism is common. We have studied 137 knees (103 patients) in order to identify a rapid and reproducible radiological feature which would indicate the need for further analysis. Overall, 67 knees (49%) had at least one radiological abnormality; 70 (51%) were considered normal. There were five cases of Dejour type-3 dysplasia of the femoral trochlea, nine of type-2 and 12 of type-1. There were 49 cases of patella alta and five of patella infera. Four knees had an abnormal lateral patellofemoral angle (patellar tilt), and in 15 knees there was more than one abnormality. Classification of trochlear dysplasia was difficult and showed poor reproducibility. This was also true for the measurement of the lateral patellofemoral angle. Patellar height was more easily measured but took time. The sulcus angle is an easily and rapidly measurable feature which was reproducible and was closely related to other features of dysplasia of the extensor mechanism. The finding of a normal sulcus angle suggested that seeking other radiological evidence of malalignment of the extensor mechanism was unlikely to reveal additional useful information. The severity of other features of dysplasia of the extensor mechanism correlated with increasing sulcus angle

A computer-based model of the knee was used to study forces in the cruciate ligaments induced by co-contraction of the extensor and flexor muscles, in the absence of external loads. Ligament forces are required whenever the components of the muscle forces parallel to the tibial plateau do not balance. When the extending effect of quadriceps exactly balances the flexing effect of hamstrings, the horizontal components of the two muscle forces also balance only at the critical flexion angle of 22 degrees. The calculations show that co-contraction of the quadriceps and hamstring muscles loads the anterior cruciate ligament from full extension to 22 degrees of flexion and loads the posterior cruciate at higher flexion angles. In these two regions of flexion, the forward pull of the patellar tendon on the tibia is, respectively, greater than or less than the backward pull of hamstrings. Simultaneous quadriceps and gastrocnemius contraction loads the anterior cruciate over the entire flexion range. Simultaneous contraction of all three muscle groups can unload the cruciate ligaments entirely at flexion angles above 22 degrees. These results may help the design of rational regimes of rehabilitation after ligament injury or repair

The posterior malleolus of the ankle is the object of increasing attention, with considerable enthusiasm for CT scanning and surgical fixation, as expressed in a recent annotation in The Bone & Joint Journal. Undoubtedly, fractures with a large posterior malleolar fragment that allow posterior talar subluxation from the mortise are served better by fixation. However, in all other situations, the existing literature does not support this widespread change in practice. The available biomechanical evidence shows that the posterior malleolus has little part to play in the stability or contact stresses of the ankle joint. Radiographic studies have not shown that CT scanning offers helpful information on pathoanatomical classification, case selection, or prognosis, or that scanning improves the likelihood of an adequate surgical reduction. Clinical studies have not shown any improvement in patient outcome after surgical fixation, and have confirmed that the inevitable consequence of increased intervention is an increased rate of complications. A careful and thoughtful evaluation of indications, risks, and benefits of this fashionable concept is required to ensure that we are deploying valuable resources with efficacy, and that we do no harm.

Cite this article: Bone Joint J 2018;100-B:566–9.

We treated 90 patients with an isolated injury to the anterior cruciate ligament (ACL) by reconstruction using a patellar tendon autograft and interference screw fixation. Of these, 82 (91%) were available for review at 24 months. Two grafts and two contralateral ACLs had ruptured during sport and there was one case of atraumatic graft resorption. Using the assessment of the International Knee Documentation Committee (IKDC), 86% of the remaining patients were normal or nearly normal. The median Lysholm knee score was 95/100 and 84% of patients were participating in moderate to strenuous activity. All had grade-0 or grade-1 Lachman, pivot-shift and anterior-drawer tests. Measurement with the KT1000 arthrometer gave a side-to-side difference of < 3 mm of anterior tibial displacement in 90%. Sixty-six radiographs were IKDC grade A and one was grade B. Pain on kneeling was present in 31% and graft site pain in 44%. At 24 months after operation all patients had excellent knee stability, a high rate of return to sport and minimal radiological evidence of degenerative change. Our series therefore represents a basis for comparison of results using other techniques and after more severe injuries