Aims. Knowledge on total knee arthroplasties (TKAs) in patients with a history of poliomyelitis is limited. This study compared implant survivorship and clinical outcomes among affected and unaffected limbs in patients with sequelae of poliomyelitis undergoing TKAs. Methods. A retrospective review of our total joint registry identified 94 patients with post-polio syndrome undergoing 116 primary TKAs between January 2000 and December 2019. The mean age was 70 years (33 to 86) with 56% males (n = 65) and a mean BMI of 31 kg/m. 2. (18 to 49). Rotating hinge TKAs were used in 14 of 63 affected limbs (22%), but not in any of the 53 unaffected limbs. Kaplan-Meier survivorship analyses were completed. The mean follow-up was eight years (2 to 19). Results. The ten-year survivorship free from revision was 91% (95% confidence interval (CI) 81 to 100) in affected and 84% (95% CI 68 to 100) in unaffected limbs. There were six revisions in affected limbs: three for periprosthetic femoral fractures and one each for periprosthetic joint infection (PJI), patellar clunk syndrome, and instability. Unaffected limbs were revised in four cases: two for instability and one each for PJI and tibial component loosening. The ten-year survivorship free from any reoperation was 86% (95% CI 75 to 97) and 80% (95% CI 64 to 99) in affected and unaffected limbs, respectively. There were three additional reoperations among affected and two in unaffected limbs. There were 12 nonoperative complications, including four periprosthetic fractures. Arthrofibrosis occurred in five affected (8%) and two unaffected limbs (4%). Postoperative range of motion decreased with 31% achieving less than 90° knee flexion by five years. Conclusion. TKAs in post-polio patients are complex cases associated with instability, and one in four require constraint on the affected side. Periprosthetic fracture was the main mode of failure. Arthrofibrosis rates were high and twice as frequent in affected limbs. Cite this article: Bone Joint J 2023;105-B(6):635–640

Aims

The aim of this study was to evaluate the incidence of liner malseating in two commonly used dual-mobility (DM) designs. Secondary aims included determining the risk of dislocation, survival, and clinical outcomes.

Aims

Total hip arthroplasty (THA) in patients with post-polio residual paralysis (PPRP) is challenging. Despite relief in pain after THA, pre-existing muscle imbalance and altered gait may cause persistence of difficulty in walking. The associated soft tissue contractures not only imbalances the pelvis, but also poses the risk of dislocation, accelerated polyethylene liner wear, and early loosening.

Aims

To assess the effect of age on clinical outcome and revision rates in patients who underwent total ankle arthroplasty (TAA) for end-stage ankle osteoarthritis (OA).

Aims

This study aimed to explore whether intraoperative nerve monitoring can identify risk factors and reduce the incidence of nerve injury in patients with high-riding developmental dysplasia.

Aims. We investigated the long-term performance of the Tripolar Trident acetabular component used for recurrent dislocation in revision total hip arthroplasty. We assessed: 1) rate of re-dislocation; 2) incidence of complications requiring re-operation; and 3) Western Ontario and McMaster Universities osteoarthritis index (WOMAC) pain and functional scores. Patients and Methods. We retrospectively identified 111 patients who had 113 revision tripolar constrained liners between 1994 and 2008. All patients had undergone revision hip arthroplasty before the constrained liner was used: 13 after the first revision, 17 after the second, 38 after the third, and 45 after more than three revisions. A total of 75 hips (73 patients) were treated with Tripolar liners due to recurrent instability with abductor deficiency, In addition, six patients had associated cerebral palsy, four had poliomyelitis, two had multiple sclerosis, two had spina bifida, two had spondyloepiphyseal dysplasia, one had previous reversal of an arthrodesis, and 21 had proximal femoral replacements. The mean age of patients at time of Tripolar insertions was 72 years (53 to 89); there were 69 female patients (two bilateral) and 42 male patients. All patients were followed up for a mean of 15 years (10 to 24). Overall, 55 patients (57 hips) died between April 2011 and February 2018, at a mean of 167 months (122 to 217) following their tripolar liner implantation. We extracted demographics, implant data, rate of dislocations, and incidence of other complications. Results. At ten years, the Kaplan–Meier survivorship for dislocation was 95.6% (95% confidence interval (CI) 90 to 98), with 101 patients at risk. At 20 years, the survivorship for dislocation was 90.6% (95% CI 81.0 to 95.5), with one patient at risk. Eight patients (7.2%) had a dislocation of their constrained liners. At ten years, the survival to any event was 89.4% (95% CI 82 to 93.8), with 96 patients at risk. At 20 years, the survival to any event was 82.5% (95% CI 71.9 to 89.3), with one patient at risk. Five hips (4.4%) had deep infection. Two patients (1.8%) developed dissociated constraining rings with pain but without dislocation, which required re-operation. Two patients (1.8%) had periprosthetic femoral fractures, without dislocation, that were treated by revision stems along with exchange of the well-functioning constrained liners. Conclusion. Constrained tripolar liners used at revision hip arthroplasty provided favourable results in the long term for treatment of recurrent dislocation and for patients at high risk of dislocation. Cite this article: Bone Joint J 2019;101-B(6 Supple B):123–126

Aims. The aims of this study were to determine the clinical and radiographic outcomes, implant survivorship, and complications of patients with a history of poliomyelitis undergoing total hip arthroplasty (THA) in affected limbs and unaffected limbs of this same population. Patients and Methods. A retrospective review identified 51 patients (27 male and 24 female, 59 hips) with a mean age of 66 years (38 to 88) and with the history of poliomyelitis who underwent THA for degenerative arthritis between 1970 and 2012. Immigrant status, clinical outcomes, radiographic results, implant survival, and complications were recorded. Results. In all, 32 THAs (63%) were performed on an affected limb, while 27 (37%) were performed on an unaffected limb. The overall ten-year survivorship free from aseptic loosening, any revision, or any reoperation were 91% (95% CI 0.76 to 0.99), 91% (95% CI 0.64 to 0.97) and 87% (95% CI 0.61 to 0.95), respectively. There were no revisions for prosthetic joint infection. There were no significant differences in any of the above parameters if THA was on the affected or unaffected control limbs. Conclusion. Patients with a history of poliomyelitis who undergo THA on the affected or unaffected limbs have similar results with overall survivorship and complication rates to those reported results in patients undergoing THA for osteoarthritis. At long-term follow-up, previous clinical concerns about increased hip instability due to post-polio abductor weakness were not observed. Cite this article: Bone Joint J 2018;100-B:733–9

Patients with neuromuscular imbalance who require total hip arthroplasty (THA) present particular technical problems due to altered anatomy, abnormal bone stock, muscular imbalance and problems of rehabilitation.

In this systematic review, we studied articles dealing with THA in patients with neuromuscular imbalance, published before April 2017. We recorded the demographics of the patients and the type of neuromuscular pathology, the indication for surgery, surgical approach, concomitant soft-tissue releases, the type of implant and bearing, pain and functional outcome as well as complications and survival.

Recent advances in THA technology allow for successful outcomes in these patients. Our review suggests excellent benefits for pain relief and good functional outcome might be expected with a modest risk of complication.

Cite this article: Bone Joint J 2018;100-B(1 Supple A):17–21.

In arthritis of the varus knee, a high tibial osteotomy (HTO) redistributes load from the diseased medial compartment to the unaffected lateral compartment.

We report the outcome of 36 patients (33 men and three women) with 42 varus, arthritic knees who underwent HTO and dynamic correction using a Garches external fixator until they felt that normal alignment had been restored. The mean age of the patients was 54.11 years (34 to 68). Normal alignment was achieved at a mean 5.5 weeks (3 to 10) post-operatively. Radiographs, gait analysis and visual analogue scores for pain were measured pre- and post-operatively, at one year and at medium-term follow-up (mean six years; 2 to 10). Failure was defined as conversion to knee arthroplasty.

Pre-operative gait analysis divided the 42 knees into two equal groups with high (17 patients) or low (19 patients) adductor moments. After correction, a statistically significant (p < 0.001, t-test,) change in adductor moment was achieved and maintained in both groups, with a rate of failure of three knees (7.1%), and 89% (95% confidence interval (CI) 84.9 to 94.7) survivorship at medium-term follow-up.

At final follow-up, after a mean of 15.9 years (12 to 20), there was a survivorship of 59% (95% CI 59.6 to 68.9) irrespective of adductor moment group, with a mean time to conversion to knee arthroplasty of 9.5 years (3 to 18; 95% confidence interval ± 2.5).

HTO remains a useful option in the medium-term for the treatment of medial compartment osteoarthritis of the knee but does not last in the long-term.

Cite this article: Bone Joint J 2016;98-B:601–7.

Instability is a common indication for early revision after both primary and revision total knee arthroplasty (TKA), accounting for up to 20% in the literature. The number of TKAs performed annually continues to climb exponentially, thus having an effective algorithm for treatment is essential. This relies on a thorough pre- and intra-operative assessment of the patient. The underlying cause of the instability must be identified initially and subsequently, the surgeon must be able to balance the flexion and extension gaps and be comfortable using a variety of constrained implants.

This review describes the assessment of the unstable TKA, and the authors’ preferred form of treatment for these difficult cases where the source of instability is often multifactorial.

Cite this article: Bone Joint J 2016;98-B(1 Suppl A):116–19.

Primary total knee arthroplasty (TKA) is a reliable procedure with reproducible long-term results. Nevertheless, there are conditions related to the type of patient or local conditions of the knee that can make it a difficult procedure. The most common scenarios that make it difficult are discussed in this review. These include patients with many previous operations and incisions, and those with severe coronal deformities, genu recurvatum, a stiff knee, extra-articular deformities and those who have previously undergone osteotomy around the knee and those with chronic dislocation of the patella.

Each condition is analysed according to the characteristics of the patient, the pre-operative planning and the reported outcomes.

When approaching the difficult primary TKA surgeons should use a systematic approach, which begins with the review of the existing literature for each specific clinical situation.

Cite this article: Bone Joint J 2015;97-B(10 Suppl A):30–9.

Degenerative problems of the hip in patients with childhood and adult onset neuromuscular disorders can be challenging to treat. Many orthopaedic surgeons are reluctant to recommend total hip replacement (THR) for patients with underlying neuromuscular disorders due to the perceived increased risks of dislocation, implant loosening, and lack of information about the functional outcomes and potential benefits of these procedures in these patients. Modular femoral components and alternative bearings which facilitate the use of large femoral heads, constrained acetabular components and perhaps more importantly, a better understanding about the complications and outcomes of THR in the patient with neuromuscular disorders, make this option viable. This paper will review the current literature and our experience with THR in the more frequently encountered neuromuscular disorders.

Cite this article: Bone Joint J 2014;96-B(11 Suppl A):27–31.

The April 2014 Research Roundup³⁶⁰ looks at: scientific writing needed in orthopaedic papers; antiseptics and osteoblasts; thromboembolic management in orthopaedic patients; nicotine and obesity in post-operative complications; defining the “Patient Acceptable Symptom State”; and cheap and nasty implants of poor quality.

Coronal plane fractures of the posterior femoral condyle, also known as Hoffa fractures, are rare. Lateral fractures are three times more common than medial fractures, although the reason for this is not clear. The exact mechanism of injury is likely to be a vertical shear force on the posterior femoral condyle with varying degrees of knee flexion. These fractures are commonly associated with high-energy trauma and are a diagnostic and surgical challenge. Hoffa fractures are often associated with inter- or supracondylar distal femoral fractures and CT scans are useful in delineating the coronal shear component, which can easily be missed. There are few recommendations in the literature regarding the surgical approach and methods of fixation that may be used for this injury. Non-operative treatment has been associated with poor outcomes. The goals of treatment are anatomical reduction of the articular surface with rigid, stable fixation to allow early mobilisation in order to restore function. A surgical approach that allows access to the posterior aspect of the femoral condyle is described and the use of postero-anterior lag screws with or without an additional buttress plate for fixation of these difficult fractures.

Cite this article: Bone Joint J 2013;95-B:1165–71.

Gunshot injuries to the shoulder are rare and difficult to manage. We present a case series of seven patients who sustained a severe shoulder injury to the non-dominant side as a result of a self-inflicted gunshot wound. We describe the injury as ‘suicide shoulder’ caused by upward and outward movement of the gun barrel as the trigger is pulled. All patients were male, with a mean age of 32 years (21 to 48). All were treated at the time of injury with initial repeated debridement, and within four weeks either by hemiarthroplasty (four patients) or arthrodesis (three patients). The hemiarthroplasty failed in one patient after 20 years due to infection and an arthrodesis was attempted, which also failed due to infection. Overall follow-up was for a mean of 26 months (12 to 44). All four hemiarthroplasty implants were removed with no feasible reconstruction ultimately possible, resulting in a poor functional outcome and no return to work. In contrast, all three primary arthrodeses eventually united, with two patients requiring revision plating and grafting. These patients returned to work with a good functional outcome. We recommend arthrodesis rather than replacement as the treatment of choice for this challenging injury.

Cite this article: Bone Joint J 2013;95-B:820–4.

The current indications for functional restoration of extension of the knee following quadriceps resection or loss require reappraisal. The contribution of pedicled and free functional muscle transfer is likely to be over-emphasised in many studies, with good functional outcomes predominantly reported only in the context of cases with residual quadriceps function. In cases with total quadriceps resection or loss, all forms of reconstruction perform poorly. Furthermore, in smaller resections with loss of two or fewer components of the quadriceps, minimal impairment of function occurs in the absence of functional reconstruction, suggesting that functional restoration may not be warranted. Thus there is a paradox in the current approach to quadriceps reconstruction, in that small resections are likely to be over-treated and large resections remain under-treated.

This review suggests a shift is required in the approach and rationale for reconstructing functional extension of the knee after quadriceps resection or loss. A classification based on current evidence is suggested that emphasises more clearly the indications and rationale for functional transfers.

We retrospectively reviewed the records of 1150 computer-assisted total knee replacements and analysed the clinical and radiological outcomes of 45 knees that had arthritis with a pre-operative recurvatum deformity. The mean pre-operative hyperextension deformity of 11° (6° to 15°), as measured by navigation at the start of the operation, improved to a mean flexion deformity of 3.1° (0° to 7°) post-operatively. A total of 41 knees (91%) were managed using inserts ≤ 12.5 mm thick, and none had mediolateral laxity > 2 mm from a mechanical axis of 0° at the end of the surgery. At a mean follow-up of 26.4 months (13 to 48) there was significant improvement in the mean Knee Society, Oxford knee and Western Ontario and McMaster Universities Osteoarthritis Index scores compared with the pre-operative values. The mean knee flexion improved from 105° (80° to 125°) pre-operatively to 131° (120° to 145°), and none of the limbs had recurrent recurvatum.

These early results show that total knee replacement using computer navigation and an algorithmic approach for arthritic knees with a recurvatum deformity can give excellent radiological and functional outcomes without recurrent deformity.

Peripheral nerve injury is an uncommon but serious complication of hip surgery that can adversely affect the outcome. Several studies have described the use of electromyography and intra-operative sensory evoked potentials for early warning of nerve injury. We assessed the results of multimodal intra-operative monitoring during complex hip surgery. We retrospectively analysed data collected between 2001 and 2010 from 69 patients who underwent complex hip surgery by a single surgeon using multimodal intra-operative monitoring from a total pool of 7894 patients who underwent hip surgery during this period. In 24 (35%) procedures the surgeon was alerted to a possible lesion to the sciatic and/or femoral nerve. Alerts were observed most frequently during peri-acetabular osteotomy. The surgeon adapted his approach based on interpretation of the neurophysiological changes. From 69 monitored surgical procedures, there was only one true positive case of post-operative nerve injury. There were no false positives or false negatives, and the remaining 68 cases were all true negative. The sensitivity for predicting post-operative nerve injury was 100% and the specificity 100%. We conclude that it is possible and appropriate to use this method during complex hip surgery and it is effective for alerting the surgeon to the possibility of nerve injury.

Inability to actively supinate the forearm makes common activities of daily living and certain vocational activities awkward or impossible to perform. A total of 11 patients with deficient supination of the arm underwent transfer of the tendon of flexor carpi ulnaris to the split tendon of brachioradialis with its bony insertion into the radial styloid left intact. Active supination beyond neutral rotation was a mean of 37.2° (25° to 49.5°) at a minimum follow-up of three years, representing a significant improvement (95% confidence interval 25 to 50, p < 0.001). Functional evaluation of the hand after this transfer showed excellent and good results in ten patients and fair in one.

The split tendon of brachioradialis as an insertion for transfer of the flexor carpi ulnaris appears to provide adequate supination of the forearm without altering the available pronation and avoids the domination of wrist extension sometimes associated with transfers of the flexor carpi ulnaris to the radial extensors of the wrist.

We report the results of using a combination of fixator-assisted nailing with lengthening over an intramedullary nail in patients with tibial deformity and shortening. Between 1997 and 2007, 13 tibiae in nine patients with a mean age of 25.4 years (17 to 34) were treated with a unilateral external fixator for acute correction of deformity, followed by lengthening over an intramedullary nail with a circular external fixator applied at the same operating session. At the end of the distraction period locking screws were inserted through the intramedullary nail and the external fixator was removed.

The mean amount of lengthening was 5.9 cm (2 to 8). The mean time of external fixation was 90 days (38 to 265). The mean external fixation index was 15.8 days/cm (8.9 to 33.1) and the mean bone healing index was 38 days/cm (30 to 60).

One patient developed an equinus deformity which responded to stretching and bracing. Another developed a drop foot due to a compartment syndrome, which was treated by fasciotomy. It recovered in three months. Two patients required bone grafting for poor callus formation.

We conclude that the combination of fixator-assisted nailing with lengthening over an intramedullary nail can reduce the overall external fixation time and prevent fractures and deformity of the regenerated bone.

This study examined the role of vitamin D as a factor accounting for fatty degeneration and muscle function in the rotator cuff. There were 366 patients with disorders of the shoulder. A total of 228 patients had a full-thickness tear (group 1) and 138 patients had no tear (group 2). All underwent magnetic resonance arthrography and an isokinetic muscle performance test. The serum concentrations of vitamin D (25(OH)D₃) were measured.

In general, a lower serum level of vitamin D was related to higher fatty degeneration in the muscles of the cuff. Spearman’s correlation coefficients were 0.173 (p = 0.001), −0.181 (p = 0.001), and −0.117 (p = 0.026) for supraspinatus, infraspinatus and subscapularis, respectively. In group 1, multivariate linear regression analysis revealed that the serum level of vitamin D was an independent variable for fatty degeneration of the supraspinatus and infraspinatus.

The serum vitamin D level has a significant negative correlation with the fatty degeneration of the cuff muscle and a positive correlation with isokinetic muscle torque.

Neurological conditions affecting the hip pose a considerable challenge in replacement surgery since poor and imbalanced muscle tone predisposes to dislocation and loosening. Consequently, total hip replacement (THR) is rarely performed in such patients. In a systematic review of the literature concerning THR in neurological conditions, we found only 13 studies which described the outcome. We have reviewed the evidence and discussed the technical challenges of this procedure in patients with cerebral palsy, Parkinson’s disease, poliomyelitis and following a cerebrovascular accident, spinal injury or development of a Charcot joint. Contrary to traditional perceptions, THR can give a good outcome in these often severly disabled patients

We studied a cohort of 26 diabetic patients with chronic ulceration under the first metatarsal head treated by a modified Jones extensor hallucis longus and a flexor hallucis longus transfer. If the first metatarsal was still plantar flexed following these two transfers, a peroneus longus to the peroneus brevis tendon transfer was also performed. Finally, if ankle dorsiflexion was < 5° with the knee extended, a Strayer-type gastrocnemius recession was performed.

The mean duration of chronic ulceration despite a minimum of six months’ conservative care was 16.2 months (6 to 31). A total of 23 of the 26 patients were available for follow-up at a mean of 39.6 months (12 to 61) after surgery. All except one achieved complete ulcer healing at a mean of 4.4 weeks (2 to 8) after surgery, and there was no recurrence of ulceration under the first metatarsal.

We believe that tendon balancing using modified Jones extensor hallucis longus and flexor hallucis longus transfers, associated in selected cases with a peroneus longus to brevis transfer and/or Strayer procedure, can promote rapid and sustained healing of chronic diabetic ulcers under the first metatarsal head.

After establishing anatomical feasibility, functional reconstruction to replace the anterolateral part of the deltoid was performed in 20 consecutive patients with irreversible deltoid paralysis using the sternoclavicular portion of the pectoralis major muscle. The indication for reconstruction was deltoid deficiency combined with massive rotator cuff tear in 11 patients, brachial plexus palsy in seven, and an isolated axillary nerve lesion in two. All patients were followed clinically and radiologically for a mean of 70 months (24 to 125). The mean gender-adjusted Constant score increased from 28% (15% to 54%) to 51% (19% to 83%). Forward elevation improved by a mean of 37°, abduction by 30° and external rotation by 9°.

The pectoralis inverse plasty may be used as a salvage procedure in irreversible deltoid deficiency, providing subjectively satisfying results. Active forward elevation and abduction can be significantly improved.

Neuralgic amyotrophy is an uncommon condition characterised by the acute onset of severe pain in the shoulder and arm, followed by weakness and atrophy of the affected muscles, and sensory loss as the pain subsides. The diversity of its clinical manifestations means that it may present to a variety of different specialties within medicine. This article describes the epidemiology, aetiopathogenesis, clinical features, differential diagnoses, investigations, treatment, course and prognosis of the condition.

We report the case of an eight-month-old girl who presented with a poliomyelitis-like paralysis in her left upper limb caused by enterovirus 71 infection. She recovered useful function after nerve transfers performed six months after the onset of paralysis. Early neurotisation can be used successfully in the treatment of poliomyelitis-like paralysis in children.

Limb lengthening by callus distraction and external fixation has a high rate of complications. We describe our experience using an intramedullary nail (Fitbone) which contains a motorised and programmable sliding mechanism for limb lengthening and bone transport. Between 2001 and 2004 we lengthened 13 femora and 11 tibiae in ten patients (seven men and three women) with a mean age of 32 years (21 to 47) using this nail. The indications for operation were short stature in six patients and developmental or acquired disorders in the rest.

The mean lengthening achieved was 40 mm (27 to 60). The mean length of stay in hospital was seven days (5 to 9). The mean healing index was 35 days/cm (18.8 to 70.9). There were no cases of implant-related infection or malunion.

A percutaneous supramalleolar osteotomy with multiple drill holes and closed osteoclasis was used to correct rotational deformities of the tibia in patients with cerebral palsy. The technique is described and the results in 247 limbs (160 patients) are reported. The mean age at the time of surgery was 10.7 years (4 to 20). The radiographs were analysed for time to union, loss of correction, and angulation at the site of the osteotomy.

Bone healing was obtained in all patients except one in a mean period of seven weeks (5 to 12). Malunion after loss of reduction at the site of the osteotomy developed in one tibia.

Percutaneous supramalleolar osteotomy of the tibia is a safe and simple surgical procedure.

Our aim was to evaluate the results of triple arthrodesis, performed without the use of supplementary bone graft. We carried out a retrospective review of 100 consecutive triple arthrodeses. All the operations had been performed by the senior author (TSS) using a standard technique. Only local bone graft from the excised joint surfaces had been used, thereby avoiding complications at the donor site.

The mean age of the patients at surgery was 58 years (18 to 84). The mean time to union was 5.1 months (3 to 17). There were 75 good, 20 fair and five poor results. There were four cases of nonunion.

Our study has shown that comparable rates of union are achieved without the need for supplementary bone graft from the iliac crest or other donor site.

Twenty complex tibial deformities due to anterior poliomyelitis in 18 patients were corrected by a modified O’Donoghue osteotomy. This technique allowed correction of the deformity in three planes. This was achieved by widening the rectangular window distally to correct both rotation and valgus and by trimming the anterior edges of the step cuts to correct flexion deformity. An above-knee cast was applied for eight to 13 weeks and the patients followed up for a mean of 3.2 years. One of the 18 patients developed delayed union because of fracture of the medial limb of the step cut. The results showed excellent correction of the three-plane deformity and there was no recurrence. This method of osteotomy is a safe and simple procedure which does not require internal fixation and allows correction of torsional and angular deformity

A new technique of shoulder fusion is presented using a posterior approach. After removal of the articular cartilage, a Rush pin is introduced from the spine of the scapula, through the glenoid into the medullary canal of the humerus. This is supplemented by tension-band wiring from the acromion to the neck of the humerus and a muscle pedicle graft attached to the acromion. A shoulder spica is applied for four to six weeks. Four patients with injuries to the upper brachial plexus and 14 with paralysis of the upper arm due to anterior poliomyelitis have been followed for three years. One of the 18 patients developed nonunion; she had removed her own cast prematurely. This method of fixation provides high shear resistance and low axial stiffness without deforming plastically. It does not affect bone growth in young patients, is effective in patients with osteoporosis, and gives a high rate of union

We have reviewed 26 patients treated by trapezius transfer for deltoid paralysis due to brachial plexus injury or old poliomyelitis. We assessed the power of shoulder abduction and the tendency for subluxation. There were good results in 16 patients (60%); five were fair and five poor. Trapezius transfer appears to give reasonable results in the salvage of abductor paralysis of the shoulder

We classified fixed pelvic obliquity in patients after poliomyelitis into two major types according to the level of the pelvis relative to the short leg. Each type was then divided into four subtypes according to the direction and severity of the scoliosis. In 46 patients with type-I deformity the pelvis was lower and in nine with type II it was higher on the short-leg side. Subtype-A deformity was a straight spine with a compensatory angulation at the lower lumbar level, mainly at L4-L5, subtype B was a mild scoliosis with the convexity to the short-leg side, subtype C was a mild scoliosis with the convexity opposite the short-leg side, and subtype D was a moderate to severe paralytic scoliosis with the convexity to the short-leg side in type I and to the opposite side in type II. A combination of surgical procedures improved the obliquity in most patients. These included lumbodorsal fasciotomy, abductor fasciotomy and stabilisation of the hip by triple innominate osteotomy with or without transiliac lengthening. In patients with type ID or type IID appropriate spinal fusion was usually necessary

We reviewed retrospectively 94 patients who had undergone soft-tissue release to correct flexion contracture of the knee to determine the incidence of postoperative hypertension. The cause of contracture in most patients was cerebral palsy (45) or old poliomyelitis (39). Twenty patients developed persistent hypertension. Two of them were symptomatic, one developing hypertensive encephalopathy. Patients who had had poliomyelitis were at a higher risk than those with cerebral palsy; the risk increased with bilateral procedures. The amount of correction achieved had no influence on the incidence of hypertension

We reviewed our experience with a modified triple innominate osteotomy for hip instability and limb shortening due to poliomyelitis in 62 adolescent and adult patients, treated from 1973 to 1990. Their ages at surgery ranged from 12 years to 35 years (average 22.3). At a mean follow-up of 4 years (2 to 18) 59 of the patients (95.2%) had substantial improvement in hip stability, and all but one had radiological improvement as determined by the acetabular angle, centre-edge angle and acetabulum-head quotient. In 59 cases in which transiliac limb lengthening was attempted, the mean gain was 1.7 cm (0.6 to 3.0). When the abductor muscles had been partially paralysed, the operation produced an appreciable increase in power in 12 of the 39 hips examined

We report our experience of surgical treatment for instability of flail knees after poliomyelitis in 228 patients. We made carefully selective use of soft-tissue release, extension osteotomy of the femur, and a patellar bone block for hyperextension. After six to nine years follow-up, 87% of the patients had retained significant improvement in stability and walking ability

We report the results of 21 femoral osteotomies performed in 18 patients for genu recurvatum and flattening of the femoral condyles after poliomyelitis. Before operation the average angle of recurvatum was 31 degrees and all the limbs required bracing. After a mean follow-up of four years there has been partial recurrence in only one case. Nine patients (10 limbs) needed no orthosis and the others had less discomfort and an improved gait. Complete remodelling of the femoral and tibial epiphyses was noted in two of the younger patients

After severe poliomyelitis, which is still relatively common in some developing countries, lateral rotation deformity of the tibia may occur. We have reviewed 51 patients treated by O'Donoghue's rotation osteotomy of the tibia. An average lateral rotation deformity of 57 degrees was fully corrected in all the patients, and in 38 of them the graft obtained during the osteotomy was used for a simultaneous Grice-Green subtalar arthrodesis in one or both feet. All the osteotomies united in an average of 11 weeks, some with relatively minor and unintentional posterior angulation. There was no posterior angulation when the length of the step cut osteotomy was 4.5 cm or more. O'Donoghue's osteotomy is a simple and safe operation, being particularly advantageous if a Grice-Green procedure is also required

A retrospective study was made of the results of surgical treatment of subluxation or dislocation of the hip in patients who had suffered from poliomyelitis. Good results were achieved in 46% and satisfactory results in 24%. The key factors for success are muscle balance, the femoral neck-shaft and anteversion angles, and the acetabular geometry. Iliopsoas transfer can augment the hip abductor power by an average of one MRC grade. Varus derotation femoral osteotomy is important to re-establish a normal neck-shaft angle and anteversion. The results of pelvic osteotomy are variable and the importance of a posterior acetabular defect is emphasised

Twenty-four patients treated for tibial shortening secondary to poliomyelitis were reviewed at least 20 years after operation. All subjects were active and only one expressed doubt about the value of tibial lengthening, considering the period of hospitalisation to have been a significant drawback. Approximately five centimetres were added to the length of the treated tibiae. Only one of the nine patients with lengthening of over five centimetres was able to walk at a rate of more than five kilometres per hour, compared with seven of the remaining 15 whose tibiae had been lengthened five centimetres or less

Although a variety of techniques have been used with varying success to induce scoliosis in animals, primates have rarely been used. A series of monkeys is presented where scoliosis developed incidentally during the routine virulence testing of live, attenuated, oral poliomyelitis vaccines by intraspinal injection. The site and extent of histological damage in the different anatomical areas of the spinal cord were examined in 25 scoliotic monkeys and 25 matched controls. Analysis of the data demonstrated that there was significantly greater damage on the convex side of the spinal cords of the scoliotic animals, particularly in the sensory areas-the posterior horn and Clarke's column. Scoliosis was not thought to be caused by clinical poliomyelitis as the involvement of the anterior horn was not significantly greater than in the scoliotic animals than in the controls. These observations are taken to support the view that scoliosis may develop as a result of asymmetrical weakness of the paraspinal muscles due to the loss of proprioceptive innervation

Two hundred and twenty-two adult crawling poliomyelitic cripples were investigated. Analysis showed that bilateral lower limb paralysis with or without trunk involvement was the most common residual lesion. Remarkably paralysis was confined to a single lower limb in six cases. The various crawling patterns can be classified into six broad groups which are described and illustrated. It is suggested that in a developing country this classification has a practical application in the assessment of patients for rehabilitation to crutch walking. Subjects in the "true quandruped progression" and "squatting gait" categories generally have an excellent potential for rehabilitation, as often do those in the "infant-like crawl" group. Caution should be exercised in attempting crutch walking for those in the "body-dragging" group, and there seems little indication for attempting to establish upright walking for those in the "buttock pivoting" and "minimal movement" groups.

A method of triple arthrodesis is described which involves inlay of the subtalar and midtarsal joints. It is applicable to the undeformed and valgus foot as is encountered in poliomyelitis, spasmodic flat foot, cerebral palsy and spina bifida. The operation was successful in controlling deformity and pain. The only significant complication was failure of fusion of the midtarsal joint which occurred in three of eighty-five feet (3-5%)

In cases of established calcaneus after anterior poliomyelitis the deformity can be greatly reduced by combining an extensive plantar release with an oblique transverse osteotomy of the calcaneus that permits displacement upwards and backwards of the posterior weight-bearing part of the bone. The procedure greatly improves the mechanical advantage of subsequent tendon transplantations to the heel. Between 1956 and 1969 fifteen such osteotomies were carried out and the long-term results have been reviewed

periosteal stripping in the long lower limb bones of thirty children with shortening after poliomyelitis was performed. All have been followed up for five years. A relative increase in length attributable to the periosteal stripping procedure was seen in the majority. The conclusions are that this simple procedure is indicated in minor degrees of limb inequality in growing children, but that the haphazard response precludes any accurate estimation of the final outcome of such a procedure

1. The results of posterior spinal fusion for paralytic scoliosis in 118 patients have been reviewed after growth had finished. The criteria for skeletal maturity were both clinical and radiological, with emphasis on ossification of the iliac apophyses. 2. The age of onset of anterior poliomyelitis and the age at which scoliosis was first noticed, as well as the extent of the muscle weakness and the curve patterns, all have a bearing on the severity of the deformity and the indication for operative treatment. 3. The method of treatment including operation is described and the complications detailed. The use of a tibial strut has now been abandoned and Harrington instrumentation has become routine. 4. There were five deaths in the series, three early and two late. 5. The difference in height, changes in respiratory function and eventual functional capacity have been analysed

1. Methods of correcting flexion contractures of the knee following poliomyelitis fail if posterior subluxation of the tibia is allowed to occur. 2. Careful serial manipulations will give straight, congruous joints in younger patients. Posterior capsulotomy does not facilitate correction. 3. Supracondylar femoral osteotomy is indicated in children over fifteen and in adults, although sometimes arthrodesis of the knee is necessary

1. The treatment of contractures at the hip secondary to poliomyelitis by Soutter's muscle slide or by Yount's fasciotomy gives excellent results. So does high femoral osteotomy, but it is not superior to the other two and should therefore be kept in reserve as a supplementary operation for the completion of correction of a deformity so gross as not to be wholly remediable by division of the soft parts. 2. Subluxation of the hip occurs only if the paralysis comes on during the first eighteen months of life and is a product not of severe paralysis but of unbalanced and often slight weakness of muscles. Correction of the invariable valgus deformity of the femoral neck by osteotomy is followed by relapse; acetabuloplasty too is unreliable. The most promising remedy seems to be some form of acetabuloplasty combined with transplantation of an iliopsoas of adequate strength into the greater trochanter. The indications for arthrodesis are few, but the results of this operation are good. 3. In the few patients with abductor weakness and little else the dipping gait may be abolished by iliopsoas transplantation

1. The nature of paralytic deformity arising in poliomyelitis, cerebral palsy and spina bifida is considered and three types of deformity–acute contracture, postural contracture and deformity from muscle imbalance are described. 2. The place of physiotherapy, splintage and surgery in the management of these varieties of paralytic deformity is discussed and the overall results of treatment are reviewed

1. A survey of 112 cases of residual poliomyelitis with leg shortening of 2·5 centimetres or more is reported. 2. In eighty-seven patients paralysed in early infancy the fibular shortening was greater than the tibial shortening. 3. The absence of the normal "to and fro" motion of the fibula causes delay in the appearance of the fibular epiphyses and retards fibular development. 4. The shortening of the fibula in infancy causes deformity at the ankle, in the tibia itself and at the knee. 5. At the ankle the poorly developed lateral malleolus causes wedging of the lower tibial epiphysis and valgus at the ankle, which is often unstable. 6. At the knee progressive genu valgum is produced and in the tibia lateral torsion occurs. 7. The clinical significance of these deformities in relation to reconstructive procedures is stressed

1. A series of patients with respiratory paralysis after anterior poliomyelitis is reported. 2. The examination routine is described and its value discussed. 3. Details are given of methods of respiratory rehabilitation and of the various pitfalls encountered, with suggestions for their avoidance. 4. The rates of recovery of vital capacity (and percentage of the expected vital capacity) in adults and children are analysed and compared with the rates given by Sharrard for nonrespiratory individual muscles in treated patients. It is shown that during the first year treated patients tend to recover approximately 3 to 4 per cent of their expected vital capacity per month rather than to regain any definite proportion of their current vital capacity

The oldest texts describing infantile paralysis (Underwood's 1789 and Salzmann's 1734) are reviewed and discussed. Salzmann's case report is likely to be a description of acute anterior poliomyelitis and is documented by details of the history, clinical picture and postmortem findings

1. Forty-eight paralytic dislocations of the hip have been studied and twenty-seven operations for correction of valgus deformity of the femoral neck have been done. 2. The differing features of dislocations occurring in poliomyelitis, cerebral palsy and meningomyelocoele are considered in relation to management after operation. 3. Early recognition of subluxation is essential to a successful varus osteotomy. An angle of 105 degrees rather than the 120 degrees previously recommended is advisable for children under the age of five. 4. Redislocation is most likely to occur in meningomyelocoele in which muscular imbalance is greatest, and in later cases where the acetabulum has become shallow by growth without the femoral head within it. It has not occurred as a late complication after weight bearing has been established, from a recurrence of valgus deformity

1. Forty-five cases of acute osteomyelitis have been reviewed with the object of determining the causes of relapse. The importance of an early diagnosis and prompt treatment is stressed, and the question of when to stop antibiotic drugs is discussed. 2. The provisional diagnosis was anterior poliomyelitis in seventeen out of forty-five patients; acute osteomyelitis was diagnosed in twelve only. The criteria for making an early diagnosis are discussed, including the value and limitation of blood culture. 3. The place of operation is discussed and certain conclusions are set out

Everywhere I visited, both in England and in other parts of Europe, I met with wonderful hospitality and friendliness. Generally our common language was English, and I felt thoroughly ashamed of my poor efforts at speaking other languages. During my tour in England, France, Germany, Austria, Italy, Denmark, Norway and Sweden I heard many new ideas propounded, and have seen many new and different methods of treatment. In particular I have been able to compare thoughts on such subjects as tuberculosis of the spine, congenital dislocation of the hip, osteoarthritis of the hip, scoliosis, many aspects of trauma, Perthes' disease, hand surgery, poliomyelitis, paraplegia, the treatment of cerebral palsy, rehabilitation of patients suffering from all kinds of orthopaedic disabilities, and surgical appliances. I am very grateful indeed to the British Orthopaedic Association for making this six-months' tour possible

1. Sixty feet operated upon either by triple or pantalar tarsal fusion for instability after poliomyelitis were re-examined ten to twenty-four years later. 2. After triple fusion with preservation of the ankle joint there was a striking absence of late osteoarthritis of the ankle, and only a low incidence of troublesome lateral instability of the ankle. The results were generally good provided the patient had reasonable power of extension of the knee. 3. Triple arthrodesis for completely flail foot in patients without active muscle control of the knee was often disappointing, so far as the limb as a whole was concerned, because of a persistent flexion deformity of the knee which usually necessitated the wearing of an appliance. 4. The results of pantalar arthrodesis for the flail foot were satisfactory. When this operation was performed (with the foot in slight equinus) in patients who lacked active extension of the knee it helped to stabilise the knee in walking by encouraging hyperextension

1 . Twenty-one cases of poliomyelitis and twenty cases of brachial plexus injury in which muscle transplantations had been performed to restore elbow flexion have been reviewed. The average follow-up period was four and a half years. 2. The results were graded objectively and subjectively. They were better when passive extension of the elbow was limited; such limitation always occurs after Steindler's operation, but infrequently after pectoral transplantation. 3. The results of pectoral transplantation are good when there is no significant shoulder paralysis; if there is shoulder weakness arthrodesis of the joint may be required to control medial rotation and adduction of the shoulder on flexion of the elbow. In brachial plexus lesions the results of pectoral transplantation may be marred by simultaneous contraction of the triceps. This can be overcome by transplanting triceps into the flexor apparatus. Triceps transplantation is rarely indicated because loss of active extension of the elbow is a grave disability. 4. Subjective results tended to be worse than objective results in brachial plexus lesions because impairment of sensibility in the hand often limited the usefulness of the limb. In striking contrast the subjective results were in general far better than the objective in patients who had had poliomyelitis. In them the smallest gain can be of functional value

A study of limb shortening after poliomyelitis in 225 children in whom paralysis was confined to one leg shows:. 1. The paralysed leg became shorter than its fellow in 219 patients (97 per cent). 2. The discrepancy in leg length only once exceeded three and a half inches. 3. Both the tibia and the femur were shorter than their fellows in 171 out of 184 studied (93 per cent). In only one patient was the femur alone shortened. 4. Three patterns of progress of shortening are described. No evidence was found that reduction of shortening ever occurs. 5. It is impossible accurately to predict shortening. In general, the more severe the paralysis the greater the shortening, but there are notable exceptions. 6. No relationship could be found between the amount of shortening and the incidence of paralysis of any individual muscle-group. 7. There was no significant difference in leg shortening in adult life between those who had developed the disease in the first two years of life and those who had developed it later. 8. A cold blue limb is not more likely to undergo severe shortening. 9. When the paralysis was confined below the knee the greatest shortening seen was one and three-quarter inches. When muscles both above and below the knee were involved severe paralysis may produce shortening up to three and a half inches. 10. Lengthening of a paralysed leg can occur during the first two years after the onset of the disease, but this is always a temporary phase. 11. The cause of leg shortening is unknown. In only two patients in this series was there evidence of premature epiphysial fusion

We believe that this technique has several advantages. After poliomyelitis recovery in the clavicular head of pectoralis major may exceed that in the sternal head; there may be considerable but incomplete recovery in both heads and it is then desirable to use all the active muscle available. Girls and women dislike conspicuous scars; the incisions used in this technique are unobtrusive when the arm is by the side

1 . An operation for strengthening the lateral abdominal muscles in children after poliomyelitis is described. It consists of transposition of the proximal part of the gluteus maximus, the tensor fasciae latae and the ilio-tibial band ("the pelvic deltoid" of Henry) to a chosen rib. 2. The results of this operation in eight consecutive cases of paralytic scoliosis, pelvic obliquity and thoraco-pelvic instability are assessed. 3. A "strong" motor allows the child to lift the pelvis against gravity, whereas with a "weak" motor the child is unable to do so efficiently. However, even a "weak" musculotendinous tendinous unit helps invariably in restoring the thoraco-pelvic stability, just as a weak "hamstring-into-patella" transplant stabilises the knee. 4. Those motors (gluteus maximus with or without tensor fasciae latae) that contract vigorously and move the free end of the ilio-tibial band for at least three centimetres on direct faradic stimulation with a bipolar electrode during the operation become ultimately strong and most efficient. 5. The unreliability of the clinical test of tensor fasciae latae in small children is discussed, and the advantage of using the gluteus maximus as the motor for the musculo-tendinous unit is emphasised. 6. Using the proximal half (or less) of the gluteus maximus for strengthening the lateral abdominal muscles does not seem to affect appreciably the strength of hip extension. This phenomenon may be explained with reasonable probability by the existence of a twofold insertion of that muscle

1. The belief that the cessation of spinal growth and curve progression coincides with the completion of growth in the iliac apophyses has been confirmed in a review of material from 224 cases. This applies also to paralytic curves. 2. In a high number of cases this ossification centre showed an asymmetrical development on the two sides of the pelvis. The appearance of a separate posterior centre of ossification is also common, and probably represents an advanced stage in the growth of the iliac apophysis. 3. Menarche and the growth of the apophyses of the vertebral bodies almost always occurred in advance of the iliac apophyses. They should be regarded as early signs of maturation, not reliable in the prognosis of curve progression. 4. The growth of the iliac apophysis appeared to be unaffected by poliomyelitis

The etiological factors concerned in paralytic scoliosis are complex. Four main types of paralytic scoliosis can be recognised. 1. The general C-curve due to the body's anatomical attempt to shift its centre of gravity towards the weaker side. Vertebral rotation is not usually marked. This type usually occurs when patients with relatively slight paralysis have been allowed up too early ; it does not usually progress to severe deformity but may occasionally do so, gradually changing into Type 2. This type usually responds well to a period of rest and muscle redevelopment in recumbency. It also responds favourably to correction and fusion because correction is easy and there is little tendency to deterioration. Many of the "successes" of correction and fusion are in this class—almost equal success would often have been gained without "correction." The spine is slightly, but not very, unstable and a relatively localised fusion will give the little extra support that is needed. 2. The "general collapse" type of curve due to extensive spinal weakness. This is the type in which simple head suspension produces marked correction. Rotation is moderate. Provided the patient's general condition is satisfactory extensive spinal fusion is usually the best treatment and produces gratifying improvement. 3. The primary lumbar curve due to a combination of pelvic obliquity, extraspinal imbalance and imbalance of the deep rotator muscles. Rotation is usually marked. Treatment must include the correction of all these factors. In mild cases correction of the pelvic obliquity is enough, but in marked cases the spine must also be corrected. The disability from a lumbar paralytic scoliosis is much greater than that from a lumbar idiopathic scoliosis of the same degree; so correction is necessary in this type. Correction in a Risser-type jacket is often inadequate and recourse to operative correction is usually required. 4. The primary thoracic curve—often associated with weakness of the scapular muscles. The indications for and methods of treatment are practically the same as in primary idiopathic thoracic curves. These curves tend to be progressive and uncompensated. Although the most popular treatment is correction and fusion, wedge osteotomy of the spine gives better correction in intractable cases. The main need is for further investigation into the etiology of paralytic scoliosis so that adequate preventive measures may be undertaken at an early stage. It is essential that every child who contracts poliomyelitis should have his back muscles examined before he gets up. If there is any suggestion of scoliosis further investigations including radiography and electromyography are essential

1. A dynamic muscle-tendon transposition is described for supplementing the power of weak lateral abdominal muscles, and the details of the operative technique are given. 2. A clinical assessment of the results in a series of twenty-four patients is given. 3. The indications for the operation in poliomyelitis are suggested

1. The distribution of the permanent paresis and paralysis in the muscles of 203 lower limbs affected by poliomyelitis is analysed and related to the destruction of motor nerve cells in the grey matter of the lumbo-sacral cord. 2. The tibialis anterior and tibialis posterior and the long muscles of the toes are more often paralysed than paretic; these muscles are innervated by short motor cell columns. Muscles such as the hip flexors and hip adductors that are more often paretic than paralysed are innervated by long cell columns. 3. Muscles innervated by the upper lumbar spinal segments are more frequently affected than those innervated by the sarcal segments. This agrees with the segmental incidence of motor cell destruction found in poliomyelitic spinal cords. 4. Each muscle or muscle group is associated in paralysis with other specific muscles. For instance, the long toe extensors with the peronei and the calf muscles (triceps surae) with the biceps femoris. Associated muscles are innervated by adjacent motor cell columns. The probability of recovery in a paralysed muscle can be determined by reference to the degree of involvement in its associated muscles. 5. The distribution of the paralysis in an individual lower limb is determined by the site and size of foci of motor cell destruction. The cell loss in certain common patterns of paralysis is described. 6. The practical application of these findings is discussed

1. The results of a three-year study of recovery in 3,033 lower limb muscles and 1,905 upper limb muscles in 142 patients are presented. 2. The rate of recovery of partly paralysed muscles is the same in all muscles and muscle groups in the lower or upper limb. Clinical differences in the ability of individual muscles to recover depend upon the proportions of their number that remain permanently paralysed. 3. The rate of recovery is slowest in adults and most rapid in young children. 4. The amount of further recovery to be expected in a muscle can be predicted from a knowledge of its grade at any time after one month from the onset of the paralysis. Fourteen-fifteenths of the total amount of recovery takes place by the beginning of the twelfth month; with rare exceptions individual muscle recovery is complete after twenty-four months. 5. Ninety per cent of muscles that are still completely paralysed after six months remain permanently paralysed. 6. The prognosis of a completely paralysed muscle is related to the level of paralysis in muscles supplied by the same spinal segments. 7. Deterioration in power in a muscle is uncommon and, when it occurs, is associated with the presence of the strong opposing force of antagonist muscles or of gravity. 8. The application of these findings to the management of cases of paralytic acute anterior poliomyelitis is discussed

1. The history of the development of the operation of sympathetic ganglionectomy for vasospasm is related. 2. A simple classification is given of the common diseases of the peripheral arteries. 3. The symptoms of peripheral arterial disease are described. 4. The investigations are discussed. 5. The treatment, both conservative and surgical, is discussed, with comments on arterial grafts. 6. Special points are made regarding poliomyelitis, acrocyanosis, Bazin's disease, cervical rib, vascular injuries and crutch arteritis. 7. The long-term results of sympathectomy are reviewed

1 . The extensor digitorum longus of the rabbit was partly denervated by section of one of its two nerve branches and examined histologically for evidence of sprouting of new fibres. 2. Sections from material fixed two and three days after operation showed terminal bundles in which varying numbers of axons and motor end-plates have degenerated. This supports the concept that the motor unit is not confined to single groups of neighbouring muscle fibres, but innervates fibres scattered throughout the muscle. 3. New fine fibres branching from intact intramuscular axons to reinnervate denervated muscle fibres were observed as early as four days after operation. 4. Such new fibres were most numerous in the early weeks after operation and their numbers then declined. Two months after operation no small fibres or simple end-plates were seen. 5. No new fibres were seen in areas of the muscle containing only denervated nerve fibres. The new fibres were formed only under the stimulus of proximity to the degenerating ones. 6. The relationship of these findings to the mechanism of recovery of human muscle affected by poliomyelitis is discussed

1. Three cases of poliomyelitis complicated by myositis ossificans are reported. 2. A search of the literature has failed to reveal any similar reported cases. 3. The cause is still obscure

The technique of storing bone by refrigeration is described and the following advantages are indicated: 1) A patient avoids a second wound and the loss of bone from some other part of the body; this is a very important matter for patients in whom poliomyelitis has affected both legs. 2) Almost unlimited bone is available to the surgeon and he is consequently able to insert very large grafts and so obtain better results

1. It is possible that neonatal sciatic palsy occurs more often than is suggested by perusal of the literature: paralysis of a foot may easily be overlooked in the new-born infant; it may be regarded as a temporary paresis due to mild birth trauma; or in later months it may be attributed to poliomyelitis. 2. Eleven cases of neonatal sciatic palsy are reported. Autopsy in one suggested that the paralysis was due to direct pressure on the sciatic nerve before birth. 3. A hypothesis is advanced by which to explain how pressure on the nerve trunk may arise in utero