Sciatic nerve injury remains a significant and devastating complication of total hip arthroplasty. Incidence as quoted in the literature ranges from 0.08% in primary joint replacement to 7.5% in revision arthroplasty. While as urgent exploration is recommended for nerve palsies associated with pain, management of sciatic nerve palsy with little or no pain is still controversial. In light of this, many patients with persistent palsies are often not referred to our specialist centre until after 6 months post-injury. The aim of this study was to review the outcomes of surgical intervention in patients presenting with sciatic nerve palsy more than 6 months after total hip arthroplasty. This retrospective cohort study identified 35 patients who underwent exploration and neurolysis of the affected sciatic nerve. All patients had documented follow-up at 1, 3, 6, 12 and 18 months to assess sensory and motor recovery. Patients were scored for sensory and motor function in the tibia and common personal nerve divisions, pre and post-operatively. The scoring system devised by Kline et al (1995) was used. Pre-operative electrophysiology was also reviewed. We found a statistically significant functional recovery following neurolysis of the sciatic nerve (p<0.01). A statistically significant relationship was also found between time to neurolysis and recovery of tibial nerve function (p = 0.02), such that greater delay to neurolysis was associated with poorer recovery. There was no significant relationship between time to neurolysis and recovery of common peroneal nerve function (p = 0.28). Our results indicate that the neurolysis of the sciatic nerve, six months or more post injury is associated with functional recovery. We feel that without surgical exploration this clinical improvement would not have occurred. Therefore, we believe that neurolysis plays a vital role at any stage of sciatic nerve injury. However, early presentation to a specialist unit is associated with better outcomes

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. Patients and Methods. We conducted a historical controlled study of patients with unilateral Crowe IV developmental dysplasia of the hip (DDH). Between October 2016 and October 2017, intraoperative nerve monitoring of the femoral and sciatic nerves was applied in total hip arthroplasty (THA). A neuromonitoring technician was employed to monitor nerve function and inform the surgeon of ongoing changes in a timely manner. Patients who did not have intraoperative nerve monitoring between September 2015 and October 2016 were selected as the control group. All the surgeries were performed by one surgeon. Demographics and clinical data were analyzed. A total of 35 patients in the monitoring group (ten male, 25 female; mean age 37.1 years (20 to 46)) and 56 patients in the control group (13 male, 43 female; mean age 37.9 years (23 to 52)) were enrolled. The mean follow-up of all patients was 13.1 months (10 to 15). Results. The two groups had no significant differences in preoperative data. In the monitoring group, ten nerve alerts occurred intraoperatively, and no neural complications were detected postoperatively. In the control group, six patients had neural complications. The rate of nerve injury was lower in the monitoring group than in the control group, but this did not achieve statistical significance. The degree of leg lengthening was significantly greater in the monitoring group than in the control group. In further analyses, patients who had previous hip surgery were more likely to have intraoperative nerve alerts and postoperative nerve injury. Conclusion. Nerve injury usually occurred during the processes of exposure and reduction. The use of intraoperative nerve monitoring showed a trend towards reduced nerve injury in THA for Crowe IV DDH patients. Hence, we recommend its routine use in patients undergoing leg lengthening, especially in those with previous hip surgery. Cite this article: Bone Joint J 2019;101-B:1438–1446

Introduction: Reconstruction of ruptured anterior cruciate ligament is a commonly performed orthopaedic procedure. There are many ways of reconstructing this ligament. One method of doing so is to harvest a tendon graft from the hamstring muscles and use it as part of the reconstruction. The tendon is usually harvested by passing a tendon stripper along the length of the tendon from an anterior knee incision. The semitendinosus and the gracilis are the hamstring muscles whose tendons are used for this. A recent case study reported injury to the sciatic nerve during the harvest of semitendinosus graft. Although morbidity arising from iatrogenic injury to nerves at the anterior aspect of the knee has been well documented, little has been written about the relationship of the sciatic nerve to the semitendinosus and gracilis in the posterior thigh. This study proposes to look at this anatomical relationship. Method: 20 legs on ten cadavers underwent the same dissection to expose the semitendinosus tendon, gracilis tendon and the sciatic nerve while maintaining their anatomical relationships. In all cases the gracilis lay further away from the sciatic nerve than the semiten-dinosus tendon. As the semitendinosus tendon was in between the semitendinosus and the sciatic nerve in all instances it was decided not to measure the distance between gracilis and the sciatic nerve. The distance between the closest point of the sciatic nerve to the tendon of semitendinosus was measured at the joint line and at intervals of 20 mm from the joint line. Results: In 45 % of the subjects the sciatic nerve and the semitendinosus tendon gradually moved further apart as the measurements were taken more proximally in the leg. In 10 % they consistently moved apart from 6 cm from the joint line onwards. In another 10% they moved consistently apart from the 8cm from the joint line measurement and in 15 % they moved apart consistently from 12 cm from the joint line. In the remaining 20 % the sciatic nerve and the semitendinosus tendon did not consistently move apart from each other until after 14 cm from the joint line. In one subject (a female of small stature) it was noted that the semitendinosus muscle lay almost directly upon the sciatic nerve. In 6 subjects the minimum distance between the sciatic nerve and the semitendinosus tendon was less than 18mm. In one subject the distance between the sciatic nerve and the semitendinosus tendon was found to be 10 mm at the closest point and remained in close proximity for a further 4 cm. Conclusion: In 55 % of our patients the sciatic nerve did not consistently move further away from the semi-tendinosus tendon as it was measured more proximally. In some subjects the minimum distance between the nerve and the tendon was less than 2 cm. Both these facts would put the sciatic nerve at risk during tendon harvesting if the tendon stripper were to move outside of the tendon during the procedure

Intro. Sciatic nerve injury (SNI) is a rare and potentially devastating complication after total hip arthroplasty (THA). Neural monitoring has been found in several studies to be useful in preventing SNI, but can be difficult to practically implement during surgery. In this study, we examine the results of using a handheld nerve stimulator for intraoperative sciatic nerve monitoring during complex THA requiring limb lengthening and/or significant manipulation of the sciatic nerve. Methods. We retrospectively reviewed a consecutive series of 11 cases (9 patients, 11 hips) with either severe developmental dysplasia of the hip (Crowe 3–4) or other underlying conditions requiring complex hip reconstruction involving significant leg lengthening and/or nerve manipulation. Sciatic nerve function was monitored intra-operatively with a handheld nerve stimulator by obtaining pre- and post-reduction conduction thresholds during component trialling. The results of nerve stimulation were then used to influence intraoperative decision- making (downsizing components, shortening osteotomy). Results. No permanent postoperative sciatic nerve complication occurred, with an average increase of 28.5mm in limb length, ranging from 6 to 51mm. In 2 out of 11 cases, a change in nerve response was identified after trial reduction, which resulted in an alternate surgical plan (femoral shortening osteotomy and downsizing femoral head). In the remainder cases, the stimulator demonstrated a response consistent with the baseline assessment, assuring that the appropriate lengthening was achieved without SNI. One patient had a transient motor and sensory peroneal nerve palsy, which resolved within two weeks. Conclusions. The intraoperative use of a handheld nerve stimulator facilitates surgical decision-making and can potentially prevent SNI. The real-time assessment of nerve function allows immediate corrective action to be taken before nerve injury occurs

The purpose of this study was to establish whether exploration and neurolysis is an effective method of treating neuropathic pain in patients with a sciatic nerve palsy after total hip replacement (THR). A total of 56 patients who had undergone this surgery at our hospital between September 1999 and September 2010 were retrospectively identified. There were 42 women and 14 men with a mean age at exploration of 61.2 years (28 to 80). The sciatic nerve palsy had been sustained by 46 of the patients during a primary THR, five during a revision THR and five patients during hip resurfacing. The mean pre-operative visual analogue scale (VAS) pain score was 7.59 (2 to 10), the mean post-operative VAS was 3.77 (0 to 10), with a resulting mean improvement of 3.82 (0 to 10). The pre- and post-neurolysis VAS scores were significantly different (p < 0.001). Based on the findings of our study, we recommend this form of surgery over conservative management in patients with neuropathic pain associated with a sciatic nerve palsy after THR. Cite this article: Bone Joint J 2013;95-B:20–2

1. The results of repair of the sciatic nerve and of its main divisions have been analysed in a series of 118 cases, the patients having been under observation for three to eighteen years (average 11·7 years). 2. A result was satisfactory if there was some return of sensibility throughout the autonomous zone (the area of skin supplied exclusively by the damaged nerve) and if the more important muscles of the leg were capable of contraction against gravity and resistance. 3. When the whole of the sciatic nerve is damaged it is necessary to present the results separately for the lateral and medial popliteal divisions. 4. Of forty-seven cases of repair of the medial popliteal nerve 79 per cent showed useful motor and 62 per cent useful sensory recovery. In three out of four cases the correspondence between the degree of motor and of sensory recovery was fairly close. 5. Of seventy-two cases of repair of the lateral popliteal nerve 36 per cent showed useful motor and 74 per cent useful sensory recovery. The latter figure must be regarded with some reserve because sensory "recovery" in the lateral popliteal zone may be due to the ingrowth of nerve fibres from contiguous normally innervated skin. Thus it is not possible to correlate motor and sensory recovery. 6. In eighteen cases of repair of the posterior tibial nerve, there was useful sensory recovery in the sole in twelve. But although there was evidence of recovery in the plantar muscles in eleven cases it was functionally valueless. 7. In repair of the medial popliteal nerve the result was better if suture had been carried out early. In repair of the lateral popliteal nerve there was no evidence that delay was harmful; but the proportion of good results was so low (as judged by motor function alone, sensory recovery being often extraneous) that this exception to a general rule cannot be taken very seriously. 8. Gaps of up to twelve centimetres–estimated after resection of the damaged nerve ends–could be closed without difficulty by the usual technique, and the extent of the gap up to that limit had no influence on the prognosis. The closure of larger gaps, when the knee must be flexed beyond a right angle, is not compatible with good recovery because the post-operative stretching of the nerve causes serious intraneural damage. 9. Nerve grafting has given poor results in repair of the sciatic nerve

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

Purpose: To quantify the functional outcome of patients who were known to have sciatic nerve involvement pre-operatively and went on to have nerve preserving surgery utilising a planned marginal excision with epineurectomy. Materials and Methods: Ten patients with large volume posterior thigh soft tissue sarcoma with known sciatic nerve involvement were reviewed between 1997 and 2004. Nine underwent surgery with extended epineurectomy of the sciatic nerve and planned marginal excision. All patients underwent staging and follow up at Sarcoma Clinic with functional assessment and TESS evaluation. Results: There were seven low and two high grade posterior thigh tumours of which nine were liposarcoma and 1 haemangiopericytoma. Two were recurrent and eight primary. There were five men and five women with a mean age of 77. Nine patients underwent planned marginal excision. Sciatic nerve involvement was 13–30cm in eight cases and in one case the sciatic nerve was abutting the tumour throughout its length. There was soft tissue reconstruction in three cases using fascial adductor or gracilis graft for sciatic nerve cover and one with superficial femoral nerve and vein resection requiring ipsilateral saphenous reconstruction. The remainder underwent direct primary reconstruction. Four patients underwent radiotherapy 46–60 Gy. There was no local recurrence of disease within 14 – 96m follow-up. There was one patient with post radiation wound breakdown that resolved. Three patients have died of unrelated causes. To date there has been no evidence of local recurrence of disease at FU. Conclusion: Planned marginal excision of low grade large volume posterior thigh sarcomas with extensive sciatic nerve involvement can be successfully treated with preservation of the sciatic nerve without significant morbidity and resultant good limb function

1. We have described what happens to patients a number of years after injury of the sciatic nerve or of its divisions; there were 329 who had been under observation for periods ranging from three to eighteen years. The neurological recovery was recorded in every case and, more important, the behaviour of the limb as appreciated by the patient. 2. Although it was generally true that good neurological recovery and good function went together there were remarkable discrepancies. Isolated paralysis of the medial popliteal or of the lateral popliteal nerve was often compatible with good function, though patients with lateral popliteal paralysis usually needed toe-raising apparatus. Even total sciatic paralysis sometimes gave little trouble. 3. Of the various types of injury, clean wounds and traction lesions led to rather better than average return of function. 4. Some degree of pain was present in about half the cases, and over-response–exaggerated and painful response to an ordinary stimulus–was present in one-third of the cases. 5. Repair of the posterior tibial nerve was rarely worth while; no less than eight out of twelve patients with this type of injury exhibited over-response. 6. One-third of the patients showed vasomotor and trophic disorders: coldness of the affected limb, erythema, thinness or pigmentation of the skin, changes in the nails or oedema. 7. Pressure sores were the most serious consequence of sciatic nerve injury and at some time or other were present in 14 per cent of our patients. The cause was deformity rather than insensibility of the sole. 8. Of the various palliative operations Lambrinudi's tarsal arthrodesis gave such disappointing results that we doubt whether the operation is worth doing. Tenodesis, revived as a time-saving expedient during the war, was a failure. For lateral popliteal paralysis anterior transplantation of tibialis posterior is excellent. 9. Amputation was done in only ten cases. When it was performed for fixed deformity with secondary ulceration the result was satisfactory. When it was done because of pain there was no relief. Amputation is, therefore, avoidable provided that vigorous steps are taken to prevent or correct deformity; it should not be done for the relief of pain

Background and objectives: Total knee replacement (TKR) produces severe postoperative pain. Peripheral nerve blocks can be used as analgesic adjuncts for TKR, but the efficacy of a sciatic nerve block as an adjunct to a femoral nerve block is controversial. The aim of this study was to compare femoral with femoral and sciatic nerve blocks in postoperative pain management of patients undergoing total knee arthroplasty (TKA). Methods: 42 patients were involved in the study. 20 patients received only a femoral nerve block, consisting of 20ml of 0.5% Chirocaine and 22 patients received femoral and sciatic nerve blocks, consisting of 20ml of 0.375% Chirocaine for the femoral nerve and 10ml of 0.5% Chirocaine for the sciatic nerve. The primary outcome measures used were visual analogue scale (VAS) scores for pain at 24 hours, 48 hours and 72 hours after the surgery, opiates consumption post-operatively and PCA use. The secondary outcomes were post-operative nausea and vomiting, sensory deficit, quadriceps contraction, straight leg raise, knee flexion, independent mobility and discharge from the hospital. Results: The results showed no difference in opiate consumption, PCA use, independent mobility and time of discharge from the hospital between the two groups. Conclusion: The study shows that the addition of a sciatic nerve block to the femoral nerve block does not provide additional benefits

Injuries to the sciatic nerve are an occasional complication of surgery to the hip and acetabulum, and traction is frequently the causative mechanism. In vitro and animal experiments have shown that increased tensile strain on peripheral nerves, when applied for prolonged periods, impairs nerve function. We have used video-extensometry to measure strain on the human sciatic nerve during total hip replacement (THR). Ten consecutive patients with a mean age of 72 years undergoing primary THR by the posterior approach were recruited, and strains in the sciatic nerve were measured in different combinations of flexion and extension of the hip and knee, before dislocation of the hip. Significant increases (p = 0.02) in strain in the sciatic nerve were observed in flexion of the hip and extension of the knee. The mean increase was 26% (19% to 30%). In animal studies increases of this magnitude have been shown to impair electrophysiological function in peripheral nerves. Our results suggest that excessive flexion of the hip and extension of the knee should be avoided during THR

Injury to the sciatic nerve following closed manipulation of a dislocated total hip replacement is rare. We present such a case in an elderly patient with partial recovery following exploration and release of the nerve

Introduction. Our Unit has been treating large volume soft tissue sarcomas involving the sciatic nerve with epineurectomy for over a decade. The aim of this study was to quantify the functional outcome of patients who were known to have sciatic nerve involvement pre-operatively and went on to have nerve preserving surgery utilising a planned marginal excision with epineurectomy. Methods. 20 patients with soft tissue sarcomas involving the sciatic nerve were studied treated between 1997 and 2010. Nineteen underwent surgery with extended epineurectomy of the sciatic nerve and planned marginal excision. All patients underwent staging and follow up at our Sarcoma Clinic with functional assessment and TESS evaluation. Results. There were sixteen low and four high-grade posterior thigh tumours of which nineteen were liposarcomas and one haemangiopericytoma. Two were recurrent and eighteen were primary. There were seven men and thirteen women with a mean age of 77 years. Nineteen patients underwent planned marginal excision. There was soft tissue reconstruction in three cases using fascial adductor or gracilis graft for sciatic nerve cover and one with superficial femoral nerve and vein resection requiring ipsilateral saphenous reconstruction. The remainder underwent direct primary reconstruction. Eight patients underwent post operative radiotherapy. There was no local recurrence of disease. There was one patient with post radiation wound necrosis that resolved. Four patients have died of unrelated causes. Discussion. Planned marginal excision (PME) of low grade large volume posterior thigh sarcomas with extensive sciatic nerve involvement can be successfully treated with preservation of the sciatic nerve without significant morbidity and excellent resultant limb function. Even with PME of high grade disease with adjuvant radiotherapy, there was no local recurrence. Whilst the procedure is technically demanding, providing strict surgical technique is employed, damage to the sciatic nerve is rare and leaves patients with an unimpaired future lifestyle

Traction injury to the sciatic nerve can occur during hamstring lengthening. The aim of this study was to monitor the influence of hamstring lengthening on conduction in the sciatic nerve using evoked electromyography (EMG). Ten children with spastic cerebral palsy underwent bilateral distal hamstring lengthening. Before lengthening, the evoked potential was recorded with the patient prone. During lengthening, it was recorded with the knee flexed to 90°, 60° and 30°, and at the end of lengthening with the hip and knee extended. In all patients, the amplitude of the evoked EMG gradually decreased with increasing lengthening. The mean decrease with the knee flexed to 60° was 34% (10 to 77), and to 30°, 86% (52 to 98) compared with the pre-lengthening amplitude. On hip extension at the end of the lengthening procedure, the EMG returned to the pre-lengthening level. Monitoring of the evoked EMG potential of the sciatic nerve during and after hamstring lengthening, may be helpful in preventing traction injury

Background and objectives: Total knee replacement (TKR) produces severe postoperative pain. Peripheral nerve blocks can be used as analgesic adjuncts after TKR. The use of peripheral nerve block has certainly reduced the use of opiates by 50%; however adding the sciatic nerve block to the femoral nerve block is controversial. The aim of this study was to compare femoral and femoral plus sciatic nerve blocks in postoperative pain management of patients undergoing TKR. Materials and Methods: Total of 42 patients were studied. Twenty patients with an average of 75yrs (51–86yrs) received femoral nerve block alone. Twenty-two patients with an average age of 69yrs (53–83yrs) received femoral plus sciatic nerve block. 0.5% Chirocaine was used for nerve blocks. There was no significant difference between two groups in terms of pre-operative pain, pre-operative deformity, ROM and patella replaced. The primary outcome measures used were visual analogue scale (VAS) pain scores at 24 hours, 48 hours and 72 hours after the surgery. The amount of opiate consumption and PCA (patient controlled analgesia) used were also recorded. The secondary outcomes were postoperative nausea and vomiting, straight leg raise, neurological deficit, knee flexion, independent mobility and discharge from the hospital. Results: The results showed significant decrease in the amount of pain in the femoral nerve block group than the combined nerve block patients. Patients who had combined nerve block complained of heaviness in the legs and were slow to mobilise. There was no significant difference in consumption of opiates, use of PCA, nausea and vomiting, independent mobility and the time of discharge from the hospital between the two groups. Conclusion: The addition of sciatic nerve block to the femoral nerve block does not provide any additional benefits in TKR

Purpose: To investigate sciatic nerve conduction during hamstring lengthening. Conclusion: Sciatic nerve traction is caused during hamstring lengthening. Summary of method, results, and discussion: Ten children with spastic cerebral palsy underwent distal hamstring lengthening, average popliteal angel before surgery was 80 degrees. Methods: The tendon of the semitendinosus was elongated by sliding lengthening. The gracilis tendon was cut and the tendons of the biceps and semimembranosus were elongated by dividing the aponeurosis. Thereafter to elongate the hamstring the hip and knee were flexed to 90 degrees and the knee slowly extended with continuous evoked EMG monitoring. Bipolar nerve stimulation placed near the sciatic nerve consisted of the delivering of rectangular impulses of amplitude 0.8-1.2 ma for 100 US duration. The EMG recordings were performed from the tibialis anterior muscle. Results: In all patients motor potential amplitude gradually decreased during extension of knee (hamstring lengthening). The average decrease of the amplitude at popliteal angle of 60 degrees was 37 percent (16-75) and at 30 degrees 83 percent (36-98). The elongation was stopped at 30° of popliteal angle. On extending the hip and knee motor potential amplitude returned to normal. Discussion: Elongation of hamstring muscle is associated with traction on the f sciatic nerve as appears by decrease in sciatic nerve motor potential amplitude. To avoid nerve injury no excessive hamstring lengthening should be done and no nerve traction should be allowed at postoperative immobilization

During revision hip surgery, damage to the sciatic nerve is due most commonly to excessive tension. While the nerve is strong in tension and is able to tolerate this remarkably, it is sensitive to lateral compression against angled structures and it is likely that tension causes injury by such pressure. In a personal series of 441 revision hip procedures, sciatic nerve injury occurred in 9 recognised cases:. 2 were complete with no useful recovery. 2 were severe with some incomplete recovery. 3 were predominantly lateral popliteal with incomplete recovery. 2 were transient and clinically fully recovered. In only two of these were the cause and the time of injury identifiable. In these cases, pain was not a serious feature but in eight separate medico-legal cases, burning pain of variable distribution has been the most serious complaint. Medical negligence has been successfully sustained on the grounds of res ipsa locitur. Regrettably, patients must be given informed consent with yet another potential hazard being listed. We have found that in normal individuals the range of straight leg raising varies between 30 and 90 degrees. Towards the limit of this range the nerve is tight and a crude cadaveric test indicated a tension force of 40 newtons! In an athlete this may be extreme and yet the nerve does not complain. Excluding direct compression (e.g. by a retractor) and thermal injury, we suggest that the tension developed during unguarded straight leg raising while the patient is still anaesthetised is a serious risk factor. After even conservative lengthening, the tension rises alarmingly during such action. It is possible that pre-existing lumbar degenerative disk disease can contribute to the hazard and be source of pain

We present simple but effective retractors used in pairs to expose the sciatic notch during Salter innominate osteotomy. We have found them to be useful for a wide range of procedures requiring similar exposure. We present them here in tribute to the memory of the designer Mercer Rang

An observation was made in our unit that sciatic nerve injury following total hip arthroplasty seemed to be more common in women. This observation has been mentioned in the literature, but no anatomical explanation has been postulated. We aimed to confirm this and suggest an anatomical explanation. Members of the British Hip Society were approached by means of a postal questionnaire regarding the sex incidence of sciatic nerve injury following both primary and revision hip surgery in their practice. In this cohort of surgeons, of 179 reported sciatic nerve injuries, 77% were in women (80% in primary hip replacement and 69% in revision surgery), which is statistically significant. We suggest that the wider outlet of the female pelvis causes the path of the sciatic nerve to pass more closely to the posterior wall of the acetabulum so making it more vulnerable to surgical injury. This hypothesis has been explored by measurements taken from CT scans of the pelvis and hips. Results do confirm the closer proximity of the nerve to the hip joint in women. We therefore advise increased care when performing hip replacement in women and suggest that this be mentioned as a gender linked risk when consenting patients prior to surgery

We describe a patient with a painful sciatic neuropathy after total hip arthroplasty. Treatment was confined to neuroleptic and analgesic agents until neurolysis at seven years abolished pain and restored function