Implant placement with inferior alveolar nerve repositioning in the posterior mandible

This case report presents inferior alveolar nerve (IAN) repositioning as a viable approach for implant placement in the mandibular molar region, where challenges of severe alveolar bone width and height deficiencies can exist. Two patients requiring implant placement in the right mandibular molar region underwent nerve transposition and lateralization. In both cases, inadequate alveolar bone height above the IAN precluded the use of short implants. The first patient exhibited an overall low alveolar ridge from the anterior to posterior regions, with a complex relationship with adjacent implant bone level and the mental nerve, complicating vertical augmentation. In the second case, although vertical bone resorption was not severe, the high positioning of the IAN within the alveolar bone due to orthognathic surgery raised concerns regarding adequate height of the implant prosthesis. Therefore, instead of onlay bone grafting, nerve transposition and lateralization were employed for implant placement. In both cases, the follow-up results demonstrated successful osseointegration of all implants and complete recovery of postoperative numbness in the lower lip and mentum area. IAN repositioning is a valuable surgical technique that allows implant placement in severely compromised posterior mandibular regions, promoting patient comfort and successful implant placement without permanent IAN damage.

Local Environment Induces Differential Gene Expression in Regenerating Nerves

INTRODUCTION

Approximately 80% of amputations are complicated by neuromas. Methods for neuroma management include nerve translocation into bone and implantation into skeletal muscle grafts, which have also facilitated the development of regenerative neural interfaces to enable fixation of prosthetics with motor and sensory feedback. However, molecular-level differences between nerves in these environments have not been investigated. This study aimed to elucidate the physiology of regenerating nerves in different settings by assessing gene expression.

MATERIALS AND METHODS

New Zealand white rabbits underwent transfemoral amputation with sciatic nerve transposition into the femur or tacked to skeletal muscle. At 5 wk, ribonucleic acid (RNA) sequencing of samples of distal nerve terminating in bone or muscle and nerve of the contralateral limb (control) identified differentially expressed genes (DEGs) and biochemical pathways (α = 0.05).

RESULTS

Three samples of nerve housed in bone, four of nerve tacked to muscle, and seven naïve controls were analyzed. Relative to controls, nerve housed in bone had little within-group variation and 13,028 DEGs, and nerve tacked to muscle had dramatic within-group variation and 12,811 DEGs. These samples upregulated the following pathways: lysosome, phagosome, antigen processing/presentation, and cell adhesion molecule. Relative to nerve housed in bone, nerve tacked to muscle had 12,526 DEGs, demonstrating upregulation of pathways of B-cell receptor signaling, focal adhesion, natural killer-cell mediated cytotoxicity, leukocyte transendothelial migration, and extracellular matrix-receptor interactions.

CONCLUSIONS

Nerve housed in bone has a more predictable molecular profile than does nerve tacked to muscle. Thus, the intramedullary canal may provide a more reliable setting for neuroma prevention and neural interfacing.

Operative treatment options for Morton's neuroma other than neurectomy - a systematic review

BACKGROUND

The effectiveness of operative treatments other than neurectomy for Morton's neuroma remains debatable despite several reported studies. This review aimed to evaluate the effects of operative treatments for Morton's neuroma other than neurectomy using an algorithmic approach and a structured critical framework to assess the methodological quality of reported studies.

METHODS

Several electronic databases were searched for articles published until August 2021 that evaluated the outcomes of operative treatments other than neurectomy in patients diagnosed with Morton's neuroma. Data searches, extraction, analysis, and quality assessments were performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, and the clinical outcomes were evaluated using objective, subjective, and negative outcomes; complications; and reoperation rate and type.

RESULTS

After reviewing 11,213 studies, 22 studies were finally included. Although a number of studies with high level of evidence are limited, we divided them according to four categories: (1) neurolysis with or without nerve transposition, (2) minimally invasive nerve decompression, (3) metatarsal osteotomy, and (4) additional procedures after nerve transection or neurectomy. All categories showed reliable outcomes except minimally invasive nerve decompression. The proportion of postoperative neurogenic symptoms was lower with neurolysis than with neurectomy.

CONCLUSION

Whether the alternative procedures were superior to neurectomy remains unclear as the number of good quality studies was limited. The proportion of postoperative neurogenic symptoms was lower with neurolysis than with neurectomy. Furthermore, performing simultaneous dorsal transposition of the nerve along with neurolysis is more recommended than neurolysis alone. Surgeons should be more careful with minimally invasive deep transverse intermetatarsal ligament release and metatarsal shortening osteotomy as their effectiveness remains inconclusive. Finally, we strongly recommend performing intramuscular embedding or intermuscular transposition of the nerve cutting end if neurectomy or nerve transection is inevitable.

LEVEL OF EVIDENCE

Level III, systematic review.

[Nerve transposition (nerve transfer): development and principles]

This review article presents the history, indications and techniques for the usual nerve transpositions in the upper extremities. By means of nerve transposition paralyzed muscles are reinnervated using dispensable donor motor axons. Many standard operations on the upper extremities are attributable to concepts of German-speaking surgeons and orthopedists. The reliable return of function by the short-range and selective motor reinnervation using nerve transfer results in a renaissance of these techniques. The spectrum of applications has been substantially extended in recent years. In order to achieve an optimal result, a subtle microsurgical technique is necessary. In this way excellent results can be achieved even for complex proximal nerve injuries.

An Updated Nerve Sparing Surgical Technique for Addressing Morton's Neuroma

Morton's neuroma is a common painful pathology that occurs in the plantar forefoot. Many treatment options exist and surgical management is used after conservative treatment options fail. While within the literature, there is a high success rate with primary neurectomy procedures, the risk of recurrence of symptoms or "stump neuromas" remains difficult to treat and can lead to debilitating pain. This article expands on a previously published article to discuss an update on a nerve sparing, microneurosurgical, procedure for the management of Morton's neuromas.

Revision of Recurrent Neuromas

Forefoot neuromas are a common pathology that is seen in a wide variety of patients. Although conservative treatment is successful with modification of shoes/inserts or injections, surgical intervention is occasionally needed to alleviate the discomfort. Most surgical procedures for neuromas have a good outcome. There are times when the outcome is not optimal and revision surgery may be needed. This article describes revision surgery techniques that may lead to an improved outcome. Also discussed is the opportunity to reduce recurrence through the understanding of neuroma biology, diagnosis, and treatment options.

Subjective and qualitative assessment of neural disturbance after inferior alveolar nerve transposition for dental implant placement

BACKGROUND

The purpose of this retrospective study was to accumulate data regarding the quality of postoperative neurosensory function after inferior alveolar nerve (IAN) transposition for dental implant placement.

METHODS

The study included seven consecutive patients who underwent IAN transposition surgery for the insertion of a dental implant into the atrophic posterior mandible. Of these, six patients (seven sides) were available for long-term assessment of postoperative IAN function. Neurosensory disturbance of the IAN was assessed objectively using the modified SW perception test reported by Semmes and Weinstein. In addition, the quality of nerve paralysis was assessed according to the criteria reported by Highet.

RESULTS

The median follow-up time was 49 months (range 12-105 months). No implant loss was observed during the follow-up. All patients experienced numbness immediately and the days after surgery. Complete recovery of neural function was observed on two sides; weak hypoesthesia was observed on two sides, moderate hypoesthesia on two sides, and severe hypoesthesia on one side. However, only one patient expressed concern about IAN function.

CONCLUSIONS

IAN transposition is a useful method for placing implants in the atrophic posterior mandible. However, the procedure is complicated, with the possibility of some degree of neurosensory disturbance, although in most of our cases, it resolved within a clinically acceptable period.

The recurrent Morton neuroma: what now?

Interdigital neuromas are a common cause of forefoot pain, and approximately 80% of patients require surgical excision for symptom relief. Although 50% to 85% of patients obtain relief after primary excision, symptoms may recur because of an incorrect diagnosis, inadequate resection, or adherence of pressure on a nerve stump neuroma. The symptom relief rate after reoperation is similar to that after primary excision. A plantar longitudinal incision provides optimal exposure, and transposition of the nerve stump into bone or muscle and avoids traction or pressure on the nerve ending that can result in a painful stump neuroma. Preoperative counseling is essential to align patient expectations with potential outcomes.

Joint denervation and neuroma surgery as joint-preserving therapy for ankle pain

Partial joint denervation or surgical neuroma therapy are alternative concepts to treat pain around the ankle joint that preserve joint function and relieve pain by interrupting neural pathways that transmit pain impulses from the joint to the brain. This review article summarizes the indication, anatomic background, operative techniques, and clinical results of joint denervation or neuroma surgery, which, although rarely reported and used, may provide a valuable alternative treatment in selected patients with neurogenous problems around the ankle.

Ulnar neuropathy at the elbow: an evidence-based algorithm

Ulnar neuropathy at the elbow is the second most common compression neuropathy of the upper extremity and poses a challenge for treating physicians. Lack of a standardized grading system, outcome measures, or surgical indications can make treatment decisions difficult to justify. Conclusions drawn from the available literature include similar rates of good to excellent outcomes for in situ decompression; transposition in the subcutaneous, submuscular, or intramuscular planes; and endoscopic decompression. Outcomes for revision surgery are generally less favorable. Development of standardized outcomes measures will be important in improving the quality and comparability of the literature on this subject.