Osteoarthritis (OA) is a chronic degenerative joint disease with cartilage degeneration, subchondral bone sclerosis, synovial inflammation and osteophyte formation. Sensory nerves play an important role in bone metabolism and in the progression of inflammation. This study explored the effects of capsaicin-induced sensory nerve denervation on OA progression in mice. This study was approved by the Institutional Animal Care and Use Committee. OA was induced via destabilization of the medial meniscus (DMM). Sensory denervation was induced by subcutaneous injection of capsaicin (90mg/kg) one week prior to DMM. One week after capsaicin injection, sensory denervation in the tibia was confirmed by immunofluorescent staining with calcitonin gene-related peptide (CGRP)-specific antibodies. Four weeks after DMM, micro-CT scans, histological analysis and RT-PCR tests were performed to evaluate OA progression. Statistical analysis was performed using SPSS 13. P values of less than 0.05 were considered statistically significant. Subcutaneous injection of capsaicin successfully induced tibial sensory denervation (n=3), which aggravated OA by increasing subchondral bone resorption. The Osteoarthritis Research Society International (OARSI) score of the capsaicin+DMM group (n=8) (11.81±2.92) was significantly higher (P=0.003) than the score of the vehicle+DMM group (n=8) (8.31±1.80). The BV/TV of the tibial subchondral bone in the capsaicin+DMM group (n=8) was 55.67%±3.08, which was significantly lower (P < 0 .001) than in the vehicle+DMM group (n=8) (86.22%±1.92). In addition, the level of expression of somatostatin in the capsaicin+DMM group (n=8) was lower than in the vehicle+DMM group (n=8) (P=0.007). Capsaicin-induced sensory denervation increased tibial subchondral bone resorption, reduced the expression of somatostatin and eventually exacerbated the existing cartilage degeneration in mice. Despite capsaicin is often used clinically to relieve OA pain, its safety is still controversial according to the OARSI guidelines for the non-surgical management of knee osteoarthritis. The findings of our study suggest that application of capsaicin, although effective in relieving pain, may accelerate the progression of existing OA

Denervation surgery has been a mainstay of our management of chronic pain in the wrist. If there is useful movement at the wrist we prefer denervation to arthrodesis. We have reviewed 22 patients at a mean of 50 months after such denervation surgery at the wrist. This was the only treatment in 16 patients; the other six also had other treatments. Pain was reduced in 16 patients, and 17 were satisfied or improved. None of the patients wished to have a supplementary arthrodesis. We stress the importance of preoperative blockade tests and of a very detailed knowledge of the local anatomy

Introduction. The management of chronic wrist pain is a challenging clinical problem. Wrist denervation aims to achieve an improvement in pain through selective neurotomy, irrespective of cause. Numerous authors have reported their experience and demonstrated a range of clinical outcomes. No studies to date have reliably identified patient populations in whom denervation surgery is most likely to succeed. We aimed to establish and investigate a new approach, combining local anaesthetic injections with a uniquely tailored functional assessment by a hand therapist, to act as a tool to identify individuals in whom surgical denervation is more likely to yield benefit. Methods. We conducted a retrospective review of 17 patients who had undergone wrist denervation procedures following our method of pre-operative assessment and selection. Patients in whom denervation was combined with other diagnostic or therapeutic surgical procedures were excluded. Each patient underwent an initial assessment by a hand therapist in which pain and functional scores were recorded using the Patient Rated Wrist Evaluation (PRWE). Further unique assessments of function were made, tailored to the functional goals and requirements of each patient. Pain scores were measured for each task. Local anaesthetic injections were then administered around the nerves considered for neurotomy and the assessments were repeated. Patients who demonstrated clear improvements in pain and function underwent surgery. Post-operative assessments of pain and function were repeated. Results. Results were analysed using the Wilcoxon signed ranks test. There was a statistically significant improvement in pain following wrist denervation surgery (p=0.06) as well as an improvement in function as measured on PRWE (p=0.01). Furthermore, the degree of improvement following local anesthetic injection correlated with the degree of improvement seen after surgery (p=0.06). Conclusions. Regardless of underlying diagnosis, improvements in pain and function following our assessment and selection process correlated with improvements seen after denervation surgery

Our aim was to determine the effect of denervation on repair-associated mRNA levels in the MCL after partial tear. Cohorts of rabbits underwent partial MCL tear with or without concomitant femoral nerve transection. Ligaments were harvested, RNA extracted and RT-PCR was performed using rabbit-specific primers for repair-associated molecules at three days, two wks, six wks and sixteen wks post-injury. Angiogenesis genes MMP3, MMP13, matrix components Collagen I and III and growth factors TGF-ß and NGF mRNA levels were increased in the denervated group at two-weeks post-injury (p< 0.05). Denervation significantly alters mRNA levels during the early stages of rabbit MCL healing. To determine the effect of denervation on repair-associated mRNA levels in the injured medial collateral ligament (MCL). Previous experiments revealed that denervation impairs healing of the MCL. We hypothesized that denervation would decrease repair-associated mRNA levels in the injured MCL when compared with normally innervated injured MCL. Adult, skeletally mature female rabbits were assigned to one of four groups: unoperated control, femoral nerve transection alone (denervated controls), MCL partial tear and denervated MCL partial tear. At three days, two weeks, six weeks or sixteen weeks post-surgery, cohorts of six rabbits from each experimental group were killed. Control rabbits were assessed at two weeks. Ligaments were harvested, RNA extracted and RT-PCR was performed using rabbit-specific primers. In the denervated injury group, mRNA levels of angiogenesis genes MMP-3 and MMP-13, matrix components Collagen I and III and growth factors TGF-ß and NGF had all increased at two-weeks post-injury, in comparison to non-denervated (p< 0.05). We also found increased levels of MMP-3 and NGF mRNA in the denervated group at sixteen weeks post injury (p< 0.05). The mRNA levels of the housekeeping gene GAPDH were increased in the denervated group only at three days post injury (p< 0.05). Of note, TGF-ß mRNA levels were significantly decreased in the denervated group at three days post injury (p< 0.05). Contrary to our initial hypothesis, denervation increases mRNA levels for many important molecules during the early stages of MCL healing. Additional research will be required to explain how and why denervation impairs ligament healing. No previous study has shown that innervation regulates mRNA levels in healing ligament

Purpose of the study: There is no satisfactory surgical solution for symptomatic osteoarthritis of the elbow joint with preserved functional motion if arthroplasty is not indicated (age, functional demand). The same is true for resistant epicondylalgia. The joint denervation techniques applied for the wrist and proximal inter-phalangeal joints have demonstrated their efficacy. We conducted an anatomic study of elbow innervation as a preliminary step to the development of a standardized surgical procedure for complete denervation of the elbow compartment. Material and methods: The study was conducted on 15 right and left unprepared fresh cadaver specimens. A standardized dissection method was used. The terminal branches of the brachial plexus were dissected proximally to distally under magnification, from the root of the arm to the mid third of the forearm. Results: Innervation of the medial compartment arose: anteriorly, from one of the two capsuloperiosteal branches arising from the medial nerve; in the epitrochleo-olecraneal gutter, from capsular branches issuing from the trunk of the radial nerve at the root of the arm and running with the ulnar nerve. The innervation of the lateral compartment arose: anteriorly, from an inconstant capsular branch issuing from the musculo-cutaneous nerve arising 4 to 7 cm downstream from the joint space and running between the bones. In the other cases, this zone was innervated by a nerve branch coming from the dorsal cutaneous nerve of the forearm issuing from the radial nerve. This branch innervated the apex of the laeral epicondyle in all cases. The posterior part of the lateral compartment was constantly innervated by a branch arising from the radial nerve in the proximal part of the arm, running between the deep hed of the triceps and the vastus lateralis, giving rise of nerves innervating the joint and terminating in the body of the anconeus muscle. Discussion: Our study enabled the description of new sources of elbow innervation not reported by Wilhelm. Conclusion: This systematization study of elbow joint innervation is a preliminary step to the development of a complete procedure for unicompartmental lateral or medial denervation of the elbow joint. The fields of application are the treatment of symptomatic osteoarthritis of the elbow joint in patients with preserved joint motion and resistant epicondylalgia

Lumbar facet joint pain cannot be reliably diagnosed clinically, the International Spinal Injection Society recommends two diagnostic local anaesthetic blocks before radiofrequency (RF) denervation [. 1. ]. Scoring systems may improve diagnostic accuracy. The two most popular scores disagree on the interpretation of pain induced by extension/rotation:. ‘Cochin Criteria’ [. 2. ]: pain on extension/rotation _ not facet joint problem. Helbig & Lee [. 3. ]: pain on extension/rotation _ facet joint problem. Methods: Retrospective study of all patients who had RF denervations of the lumbar facet joints in 2004. Patients were selected clinically and did not undergo diagnostic blocks. Cochin criteria, Helbig & Lee scores, work status, and outcome were taken from the case notes. Likelihood ratios were calculated for the scores, their individual components, and work status. Results: 145 patients underwent RF facet joint denervation, for 127 all data was available. In 68 patients the procedure was successful (53.5%). Conclusion: Neither the Cochin Criteria nor the Helbig & Lee score can predict the response to radiofrequency denervation of the lumbar facet joints. Pain on extension/rotation weakly indicates a poor response to facet joint denervation. X-rays do not help with the diagnosis. Social factors may be more important than clinical signs

1. A method of denervating the elbow joint, based upon observations on the articular branches of the main nerve trunks, is presented. 2. In a small group of cases with post-traumatic arthritis and osteoarthritis, relief of pain and restoration of painless movement has been gained. 3. There was recurrence of pain after six months in one patient with acute rheumatoid arthritis; in such cases denervation is not recommended until further study is completed. 4. Denervation must be as complete as possible and full exposure with stripping of nerve trunks is recommended. There have been no complications. 5. The results in this small series of cases are encouraging, but patients should be warned that there will be no significant increase in the range of movement, and that a normal joint is not to be expected. 6. Articular neurectomy is still on trial. If the limitations are recognised, the procedure may have a useful place in the relief of pain in the elbow joint

Aims. A systematic review of the available literature comparing the outcomes of radiofrequency denervation to sham procedure in treating chronic low back pain caused by lumber zygapophysial joint pathology. Methods. Medline and EMBASE databases were searched for English language articles from 2005 to July 2010. Articles were considered for review if they satisfied the inclusion criteria: Randomised Controlled Trials(RCT) comparing radiofrequency neurotomy(RFN) to a ‘placebo’ procedure in patients with chronic low back pain caused by facet joint osteoarthritis. Adult patients of both sexes above 17 years of age who complained of continuous low back pain for more than 6 months with focal tenderness over the facet joints. Outcome measures of interest are pain improvement, physical activity, analgesic use, quality of life variables, range of motion of the lumbar spine and hip movement. Critical appraisal of the selected studies was carried out using the CASP appraisal tool for RCT. Results. Two articles were identified. Both demonstrated a statistically significant improvement in the pain (p<0.05) using a visual analogue scale in the RFN group compared to the sham procedure. Only one trial demonstrated a corresponding reduction in analgesic use. There was no consensus of improvement of quality of life factors in either study as compared to placebo. Conclusion. Radiofrequency denervation is better than sham procedure in treating pain caused by facet joint osteoarthritis with minimal adverse effects in the short term. A higher powered trial using a larger cohort and longer follow up is required to resolve some of the equivocal results. Conflicts of Interest. None. Source of Funding. None

Percutaneous radiofrequency neurotomy of the lumbar medial branch is a widely accepted treatment for pain of the lumber intervertebral joints. However its success rate has varied among authors. One reason for this inconsistency is the lack of method for objective evaluation of whether the nerve has been sufficiently denervated or not. This study has made possible real time and accurate monitoring of whether electrocauterization is properly executed or not. The subjects were 50 patients with law back pain persisting for 3 months or longer in whom facet block or medial branch block of posterior ramus was only temporarily effective. They ranged in age from 19 to 76 years (mean 54 years) and were followed up for 1 year to 7 years and 1 month (mean 2 years and 9 months). In our percutaneous radiofrequency neurotomy, the target point of denervation is defined as the groove between the mammillary process and accessory process (1) and complex muscle action potentials (CMAPs) of multifidus muscles are used as an index for objective evaluation of the effects of denervation. Improvements were observed immediately after the treatment in 39 patients (78%). The effects of this treatment, once attained, remained over a long period, and the duration of effects was 18–20 months as estimated by the cumulative success rate calculated using the Kaplan-Meyer method. Patients must be carefully selected for percutaneous radiofrequency neurotomy to be consistently effective, all the more because the procedure is simple. However, it is a reliable method for denervation of the lumbar medial branch and long-term relief from pain can be expected. This therapy, therefore, is an effective alternative for the treatment of chronic pain due to lumbar intervertebral arthropathy that resists conservative treatments and disturbs daily living

Aims: To assess the paraspinal muscle innervation and endurance in LSSMethods: Study included 25 patients with clinically and radiologically diagnosed LSS. Electromyography (EMG) of the paraspinal muscles was performed at the L3 to S1 levels bilaterally using a concentric needle. At least 20 insertions were analysed from each muscle to detect abnormal spontaneous activity associated with axonal damage (þbrillation potentials, positive sharp waves and complex repetitive discharges). Paraspinal muscle activity during trunk ßexion-extension movement and muscle endurance during dynamic isoinertial back endurance test were assessed by surface EMG. Muscle fatigue was calculated using mean power frequency (MPF) analysis. Results: Abnormal þndings in needle EMG of the paraspinal muscles were observed in 18 out of the 22 (81.8%) examined patients. Abnormal ßexionextension activation of the paraspinal muscles was observed in all examined patients. The MPF change was signiþcantly smaller than in previously evaluated healthy subjects and non-speciþc CLBP patients (P< 0.001) not suffering from symptoms of LSS. Para-spinal muscle fatigability was not associated with the denervation of the muscles. Conclusions: Denervation and abnormal activation of lumbar paraspinal muscles are frequent þndings in non-operated LSS patients. The paraspinal muscle endurance of the patients was unexpectedly good

Percutaneous radiofrequency facet joint denervation (RFJD) has been used increasingly since being described by Shealy1 for the non-surgical treatment of chronic low back pain. Extensive literature exists on this technique with a number of randomised control studies suggesting efficacy against Placebo2,3. However, the efficacy and reliability of repeat RFJD for chronic back pain is unknown. A prospective study was carried out on a consecutive series of 57 patients undergoing repeat lumbar RFJD between 2004 & 2006. 57 consecutive patients treated by the senior author (OLO) between April 2004–June 2006 were included in a prospective analysis using a visual analogue score (VAS) and the low back outcome score (LBOS). All 57 participants completed a telephone questionnaire at follow up. There were no complications. At a median average follow up of 14 months overall, clinical outcomes demonstrated moderate improvement in the majority of patients with poor rating at LBOS decreasing from 54.3% pre- to 40.3% post-RFJD. The overall degree of satisfaction was 77.2%. The overall median duration of pain relief was 10 months. Our study suggests that repeat RFJD appears to have reliable and satisfactory results when repeated with most patients reporting a high degree of satisfaction and with the clinical outcome similar to the initial procedure

Aim of the study: The evaluation of denervation efficiency in the treatment of the arthritis of the base of the thumb. Material and method. Between 2001– 2004, 15 patients were surgically treated for arthritis of the basis of the thumb. There were all females of an average age of 53 years. In all patients the procedure was done ambulatory under local anesthesia. After completing a protocol form, regarding pain motion and power of the thumb, an incision was made at the level of the wrist crease extended from the level of FCR to the level of the 2nd extensor compartment. Through this incision the articular branches which conform the studies of Wilhem and Fusche supply the 1st CMC joint were divided. A supplementary incision for the first intermetacarpal space was made. The patients were free to return to their activities the third postoperative day and they were reviewed after 3, 6, 12, 24 months by an independent doctor. Their data were also recorded conform the protocol. Results: Twelve patients out of 15 had excellent improvement of their strength. Pinch and grip power was doubled. Mobility of the thumb according to Kapanji scale was improved in all cases. Pain was reduced in 65% average. The patients were satisfied from the operation. There was one patient with poor improvement and two patients who never shown up at the follow-up. As the last were at the beginning of our learning curve we think that could have a less satisfactory result. Discussion: The method is simple with minimal impact to the patient activity or life. It gives good results in 65% –75% and leaves further operative procedures possible. Although there not enough data yet for this procedure and our number of cases is small with short follow-up we believe that it is a nice procedure, it satisfies both the patient and the surgeon regarding the overall improvement of mobility and pain

1 . The repair of a simple crush injury was studied in rats, in both normally innervated and completely denervated muscle. In each case the histological findings at periods from two hours to thirty-two weeks are described.

2. The denervated muscle showed active and effective repair.

3. A comparison with the findings in normally innervated muscle establishes that the cellular processes of repair do not depend on connections with the central nervous system.

The right sciatic nerve of 50 one-month-old male rats was cut under general anaesthesia. Groups of animals were sacrificed at intervals of up to 12 weeks after operation and the length of the femora, tibiae and first and fifth metatarsals were measured with a caliper accurate to 0.05 mm. From the first week, both metatarsals were between 3% and 5% shorter on the denervated side, but there was no further increase of the discrepancy. The femora were less than 1% longer in the denervated limb at the second and eighth week. No difference was found between the lengths of the tibiae. The various factors which could possibly be responsible for these findings are discussed.

The incidence of anterior knee pain following total knee replacement (TKR) is reported to be as high as 49%. The source of the pain is poorly understood but the soft tissues around the patella have been implicated.

In theory circumferential electrocautery denervates the patella thereby reducing efferent pain signals. However, there is mixed evidence that this practice translates into improved outcomes.

We aimed to investigate the clinical effect of intra-operative circumpatellar electrocautery in patients undergoing TKR using the LCS mobile bearing or Kinemax fixed bearing TKR. A total of 200 patients were randomised to receive either circumpatellar electrocautery (diathermy) or not (control). Patients were assessed by visual analogue scale (VAS) for anterior knee pain and Oxford knee score (OKS) pre-operatively and three months, six months and one year post-operatively. Patients and assessors were blinded.

There were 91 patients in the diathermy group and 94 in the control. The mean VAS improvement at one year was 3.9 in both groups (control; -10 to 6, diathermy; -9 to 8, p < 0.001 in both cases, paired, two-tailed t-test). There was no significant difference in VAS between the groups at any other time. The mean OKS improvement was 17.7 points (0 to 34) in the intervention group and 16.6 (0 to 42) points in the control (p = 0.36). There was no significant difference between the two groups in OKS at any other time.

We found no relevant effect of patellar electrocautery on either VAS anterior knee pain or OKS for patients undergoing LCS and Kinemax TKR.

The December 2022 Wrist & Hand Roundup. 360. looks at: Anti-tumour necrosis factor therapy for early-stage Dupuytren’s disease; Patient experiences of scaphoid waist fractures and their treatment; Postoperative complications following open a1 pulley release for a trigger finger or thumb; How certain are findings in distal radius fractures: a systematic review of randomized controlled trials; Partial wrist denervation in wrist osteoarthritis: patient-reported outcomes and objective function; Dorsal bridge plating versus bridging external fixation for management of complex distal radius fractures; How is reduction lost in distal radius fractures in females aged 50 years and older; The HAND-Q: psychometrics of a new patient-reported outcome measure for clinical and research applications

Introduction. Degenerative meniscal tears are the most common meniscal lesions, representing huge clinical and socio-economic burdens. Their role in knee osteoarthritis (OA) onset and progression is well established and demonstrated by several retrospective studies. Effective preventive measures and non-surgical treatments for degenerative meniscal lesions are still lacking, also because of the lack of specific and accurate animal models in which test them. Thus, we aim to develop and validate an accurate animal model of meniscus degeneration. Method. Three different surgical techniques to induce medial meniscus degenerative changes in ovine model were performed and compared. A total of 32 sheep (stifle joints) were subjected to either one of the following surgical procedures: a) direct arthroscopic mechanical meniscal injury; b) peripheral devascularization and denervation of medial meniscus; c) full thickness medial femoral condyle cartilage lesion. In all the 3 groups, the contralateral joint served as a control. Result. From a visual examination of the knee joint emerged a clear difference between control and operated groups, in the menisci but also in the cartilage, indicating the onset of OA-related cartilage degeneration. The meniscal and cartilaginous lesions were characterized by different severity and location in the different groups. For instance, a direct meniscal injury caused cartilaginous lesions especially in the medial part of the condyles, and the other approaches presented specific signature. Evaluation of scoring scales (e.g. ICRS score) allowed the quantification of the damage and the identification of differences among the four groups. Conclusion. We were effectively able to develop and validate a sheep model of meniscal degeneration which led to the onset of OA. This innovative model will allow to test in a pre-clinical relevant setting innovative approaches to prevent meniscal-related OA. Funding. Project PNRR-MAD-2022-12375978 funded by Italian Ministry of Health

Aims. The pathogenesis of intraneural ganglion cysts is controversial. Recent reports in the literature described medial plantar intraneural ganglion cysts (mIGC) with articular branches to subtalar joints. The aim of the current study was to provide further support for the principles underlying the articular theory, and to explain the successes and failures of treatment of mICGs. Patients and Methods. Between 2006 and 2017, five patients with five mICGs were retrospectively reviewed. There were five men with a mean age of 50.2 years (33 to 68) and a mean follow-up of 3.8 years (0.8 to 6). Case history, physical examination, imaging, and intraoperative findings were reviewed. The outcomes of interest were ultrasound and/or MRI features of mICG, as well as the clinical outcomes. Results. The five intraneural cysts followed the principles of the unifying articular theory. Connection to the posterior subtalar joint (pSTJ) was identified or suspected in four patients. Re-evaluation of preoperative MRI demonstrated a degenerative pSTJ and denervation changes in the abductor hallucis in all patients. Cyst excision with resection of the articular branch (four), cyst incision and drainage (one), and percutaneous aspiration/steroid injection (two) were performed. Removing the connection to the pSTJ prevented recurrence of mIGC, whereas medial plantar nerves remained cystic and symptomatic when resection of the communicating articular branch was not performed. Conclusion. Our findings support a standardized treatment algorithm for mIGC in the presence of degenerative disease at the pSTJ. By understanding the pathoanatomic mechanism for every cyst, we can improve treatment that must address the articular branch to avoid the recurrence of intraneural ganglion cysts, as well as the degenerative pSTJ to avoid extraneural cyst formation or recurrence. Cite this article: Bone Joint J 2018;100-B:183–9

The August 2014 Spine Roundup. 360 . looks at: rhBMP complicates cervical spine surgery; posterior longitudinal ligament revisited; thoracolumbar posterior instrumentation without fusion in burst fractures; risk modelling for VTE events in spinal surgery; the consequences of dural tears in microdiscectomy; trends in revision spinal surgery; radiofrequency denervation likely effective in facet joint pain and hooks optimally biomechanically transition posterior instrumentation