Osteoarthritis (OA) is a highly prevalent degenerative joint disorder characterized by joint pain and physical disability. Aberrant subchondral bone induces pathological changes and is a major source of pain in OA. In the subchondral bone, which is highly innervated, nerves have dual roles in pain sensation and bone homeostasis regulation. The interaction between peripheral nerves and target cells in the subchondral bone, and the interplay between the sensory and sympathetic nervous systems, allow peripheral nerves to regulate subchondral bone homeostasis. Alterations in peripheral innervation and local transmitters are closely related to changes in nociception and subchondral bone homeostasis, and affect the progression of OA. Recent literature has substantially expanded our understanding of the physiological and pathological distribution and function of specific subtypes of neurones in bone. This review summarizes the types and distribution of nerves detected in the tibial subchondral bone, their cellular and molecular interactions with bone cells that regulate subchondral bone homeostasis, and their role in OA pain. A comprehensive understanding and further investigation of the functions of peripheral innervation in the subchondral bone will help to develop novel therapeutic approaches to effectively prevent OA, and alleviate OA pain. Cite this article: Bone Joint Res 2022;11(7):439–452

Upper limb amputations, ranging from transhumeral to partial hand, can be devastating for patients, their families, and society. Modern paradigm shifts have focused on reconstructive options after upper extremity limb loss, rather than considering the amputation an ablative procedure. Surgical advancements such as targeted muscle reinnervation and regenerative peripheral nerve interface, in combination with technological development of modern prosthetics, have expanded options for patients after amputation. In the near future, advances such as osseointegration, implantable myoelectric sensors, and implantable nerve cuffs may become more widely used and may expand the options for prosthetic integration, myoelectric signal detection, and restoration of sensation. This review summarizes the current advancements in surgical techniques and prosthetics for upper limb amputees.

Cite this article: Bone Joint J 2021;103-B(3):430–439.

Deep gluteal syndrome is an increasingly recognized disease entity, caused by compression of the sciatic or pudendal nerve due to non-discogenic pelvic lesions. It includes the piriformis syndrome, the gemelli-obturator internus syndrome, the ischiofemoral impingement syndrome, and the proximal hamstring syndrome. The concept of the deep gluteal syndrome extends our understanding of posterior hip pain due to nerve entrapment beyond the traditional model of the piriformis syndrome. Nevertheless, there has been terminological confusion and the deep gluteal syndrome has often been undiagnosed or mistaken for other conditions. Careful history-taking, a physical examination including provocation tests, an electrodiagnostic study, and imaging are necessary for an accurate diagnosis.

After excluding spinal lesions, MRI scans of the pelvis are helpful in diagnosing deep gluteal syndrome and identifying pathological conditions entrapping the nerves. It can be conservatively treated with multidisciplinary treatment including rest, the avoidance of provoking activities, medication, injections, and physiotherapy.

Endoscopic or open surgical decompression is recommended in patients with persistent or recurrent symptoms after conservative treatment or in those who may have masses compressing the sciatic nerve.

Many physicians remain unfamiliar with this syndrome and there is a lack of relevant literature. This comprehensive review aims to provide the latest information about the epidemiology, aetiology, pathology, clinical features, diagnosis, and treatment.

Cite this article: Bone Joint J 2020;102-B(5):556–567.

Aims

The aim of this study was to evaluate the time course of changes in parameters of diffusion tensor imaging (DTI) such as fractional anisotropy (FA) and apparent diffusion coefficient (ADC) in patients with symptomatic lumbar disc herniation. We also investigated the correlation between the severity of neurological symptoms and these parameters.

The widespread use of MRI has revolutionised the diagnostic process for spinal disorders. A typical protocol for spinal MRI includes T1 and T2 weighted sequences in both axial and sagittal planes. While such an imaging protocol is appropriate to detect pathological processes in the vast majority of patients, a number of additional sequences and advanced techniques are emerging. The purpose of the article is to discuss both established techniques that are gaining popularity in the field of spinal imaging and to introduce some of the more novel ‘advanced’ MRI sequences with examples to highlight their potential uses.

Cite this article: Bone Joint J 2015;97-B:1683–92.

Total hip replacement (THR) is a very common procedure undertaken in up to 285 000 Americans each year. Patient satisfaction with THR is very high, with improvements in general health, quality of life, and function while at the same time very cost effective. Although the majority of patients have a high degree of satisfaction with their THR, 27% experience some discomfort, and up to 6% experience severe chronic pain. Although it can be difficult to diagnose the cause of the pain in these patients, this clinical issue should be approached systematically and thoroughly. A detailed history and clinical examination can often provide the correct diagnosis and guide the appropriate selection of investigations, which will then serve to confirm the clinical diagnosis made.

Cite this article: Bone Joint J 2013;95-B, Supple A:70–3.

The April 2013 Wrist & Hand Roundup³⁶⁰ looks at: whether botox is just for Hollywood; supercharging nerve repairs; YouTube research; options for Keinbock’s disease; volar plates; driving and plasters; symptomatic radial malunion; and MRI and acute scaphoid fractures.

We undertook a retrospective analysis of 306 procedures on 233 patients, with a mean age of 12 years (1 to 21), in order to evaluate the use of somatosensory evoked potential (SSEP) monitoring for the early detection of nerve compromise during external fixation procedures for limb lengthening and correction of deformity. Significant SSEP changes were identified during 58 procedures (19%). In 32 instances (10.5%) the changes were transient, and resolved once the surgical cause had been removed. The remaining 26 (8.5%) were analysed in two groups, depending on whether or not corrective action had been performed in response to critical changes in the SSEP recordings. In 16 cases in which no corrective action was taken, 13 (81.2%, 4.2% overall) developed a post-operative neurological deficit, six of which were permanent and seven temporary, persisting for five to 18 months. In the ten procedures in which corrective action was taken, four patients (40%, 1.3% overall) had a temporary (one to eight months) post-operative neuropathy and six had no deficit.

After appropriate intervention in response to SSEP changes, the incidence and severity of neurological deficits were significantly reduced, with no cases of permanent neuropathy. SSEP monitoring showed 100% sensitivity and 91% specificity for the detection of nerve injury during external fixation. It is an excellent diagnostic technique for identifying nerve lesions when they are still highly reversible.

This study was designed to test the hypothesis that the sensory innervation of bone might play an important role in sensing and responding to low-intensity pulsed ultrasound and explain its effect in promoting fracture healing. In 112 rats a standardised mid-shaft tibial fracture was created, supported with an intramedullary needle and divided into four groups of 28. These either had a sciatic neurectomy or a patellar tendon resection as control, and received the ultrasound or not as a sham treatment. Fracture union, callus mineralisation and remodelling were assessed using plain radiography, peripheral quantitative computed tomography and histomorphology.

Daily ultrasound treatment significantly increased the rate of union and the volumetric bone mineral density in the fracture callus in the neurally intact rats (p = 0.025), but this stimulating effect was absent in the rats with sciatic neurectomy. Histomorphology demonstrated faster maturation of the callus in the group treated with ultrasound when compared with the control group. The results supported the hypothesis that intact innervation plays an important role in allowing low-intensity pulsed ultrasound to promote fracture healing.

We reviewed 101 patients with injuries of the terminal branches of the infraclavicular brachial plexus sustained between 1997 and 2009. Four patterns of injury were identified: 1) anterior glenohumeral dislocation (n = 55), in which the axillary and ulnar nerves were most commonly injured, but the axillary nerve was ruptured in only two patients (3.6%); 2) axillary nerve injury, with or without injury to other nerves, in the absence of dislocation of the shoulder (n = 20): these had a similar pattern of nerve involvement to those with a known dislocation, but the axillary nerve was ruptured in 14 patients (70%); 3) displaced proximal humeral fracture (n = 15), in which nerve injury resulted from medial displacement of the humeral shaft: the fracture was surgically reduced in 13 patients; and 4) hyperextension of the arm (n = 11): these were characterised by disruption of the musculocutaneous nerve. There was variable involvement of the median and radial nerves with the ulnar nerve being least affected.

Surgical intervention is not needed in most cases of infraclavicular injury associated with dislocation of the shoulder. Early exploration of the nerves should be considered in patients with an axillary nerve palsy without dislocation of the shoulder and for musculocutaneous nerve palsy with median and/or radial nerve palsy. Urgent operation is needed in cases of nerve injury resulting from fracture of the humeral neck to relieve pressure on nerves.

We describe 261 peripheral nerve injuries sustained in war by 100 consecutive service men and women injured in Iraq and Afghanistan. Their mean age was 26.5 years (18.1 to 42.6), the median interval between injury and first review was 4.2 months (mean 8.4 months (0.36 to 48.49)) and median follow-up was 28.4 months (mean 20.5 months (1.3 to 64.2)). The nerve lesions were predominantly focal prolonged conduction block/neurapraxia in 116 (45%), axonotmesis in 92 (35%) and neurotmesis in 53 (20%) and were evenly distributed between the upper and the lower limbs. Explosions accounted for 164 (63%): 213 (82%) nerve injuries were associated with open wounds. Two or more main nerves were injured in 70 patients. The ulnar, common peroneal and tibial nerves were most commonly injured. In 69 patients there was a vascular injury, fracture, or both at the level of the nerve lesion. Major tissue loss was present in 50 patients: amputation of at least one limb was needed in 18. A total of 36 patients continued in severe neuropathic pain.

This paper outlines the methods used in the assessment of these injuries and provides information about the depth and distribution of the nerve lesions, their associated injuries and neuropathic pain syndromes.

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.

In this study of 41 patients, we used proteomic, Western blot and immunohistochemical analyses to show that several reactive oxygen species scavenging enzymes are expressed differentially in patients with primary osteoarthritis and those with non-loosening and aseptic loosening after total hip replacement (THR). The patients were grouped as A (n = 16, primary THR), B (n = 10, fixed THR but requiring revision for polyethylene wear) and C (n = 15, requiring revision due to aseptic loosening) to verify the involvement of the identified targets in aseptic loosening. When compared with Groups A and B, Group C patients exhibited significant up-regulation of transthyretin and superoxide dismutase 3, but down-regulation of glutathione peroxidase 2 in their hip synovial fluids. Also, higher levels of superoxide dismutase 2 and peroxiredoxin 2, but not superoxide dismutase 1, catalase and glutathione perioxidase 1, were consistently detected in the hip capsules of Group C patients.

We propose that dysregulated reactive oxygen species-related enzymes may play an important role in the pathogenesis and progression of aseptic loosening after THR.

We describe a 23-year-old woman with neuritis ossificans involving the tibial, common peroneal and lateral sural nerves. She presented with chronic debilitating posterior knee pain. An MRI scan showed masses in these nerves, biopsy of which revealed a histological diagnosis of neuritis ossificans. Treatment with OxyContin and Neurotin for two years resulted in resolution of symptoms. Follow-up MRI demonstrated a resolution of two of the three masses. There was a persistent area of ossification without associated oedema in the common peroneal nerve. Neuritis ossificans has the histological appearance of myositis ossificans and follows a similar clinical course. The success of conservative treatment in this case suggests that the potential complications of surgical excision can be avoided.

Coccydynia is a painful disorder characterised by coccygeal pain which is typically exaggerated by pressure. It remains an unsolved mystery because of the perceived unpredictability of the origin of the pain, some psychological traits that may be associated with the disorder, the presence of diverse treatment options, and varied outcomes. A more detailed classification based on the aetiology and pathoanatomy of coccydynia helps to identify patients who may benefit from conservative and surgical management.

This review focuses on the pathoanatomy, aetiology, clinical features, radiology, treatment and outcome of coccydynia.