Clinical outcomes after primary repair for thumb ulnar collateral ligament ruptures: a systematic review and meta-analysis

There is no consensus on the best surgical technique for treating thumb ulnar collateral ligament (UCL) ruptures. This systematic review and meta-analysis investigates which primary repair technique and postoperative immobilization protocol result in the best clinical outcomes. A literature search was conducted in Embase, Medline ALL Ovid, Web of Science Core Selection and Cochrane Central Register of Controlled Trials. Pain, stability, tip pinch strength, key pinch strength, grip strength, return to work and metacarpophalangeal joint range of motion were collected as postoperative outcomes. In total, 29 studies were included. All surgical techniques resulted in satisfactory clinical outcomes, with no significant differences between bone anchor reinsertion, suture fixation, K-wire fixation and a combination of techniques. K-wire immobilization resulted in worse postoperative pain, but similar stability compared to immobilization without a K-wire. Clinical outcomes after thumb UCL repair are excellent, with no differences in clinical outcomes noted among surgical techniques.

Quality of life in 583 head and neck cancer survivors assessed with the FACE-Q head and neck cancer module

OBJECTIVES

Long-term health-related quality of life (HRQOL) is frequently affected in head and neck cancer (HNC) survivors. Due to the shortage of studies investigating long-term patient-reported outcomes, we investigated long-term HRQOL using the novel FACE-Q HNC Module.

METHODS

A retrospective cross-sectional single-center study was performed, including all patients who underwent curative treatment for HNC between 2006 and 2013. All eligible patients (n = 863) were invited to participate of whom 540 completed the questionnaires. Additionally, a prospective longitudinal cohort of 43 HNC patients treated between 2020 and 2022 was included who preoperatively filled in the FACE-Q, and at three, six, and 12 months postoperatively. HRQOL domain scores were analyzed to visualize group characteristics by tumor site and type of surgical resection.

RESULTS

Both surgical and non-surgical HNC treatments predominantly affected long-term functional HRQOL domains (eating, salivation, speech, and swallowing), eating distress, and speaking distress, with distinct profiles depending on tumor site and type of treatment. In contrast, few long-term intergroup differences between HNC patients were observed for appearance, smiling, drooling distress, and smiling distress. Longitudinal data showed significant deterioration across all functional HRQOL domains in the short-term following treatment. Patients predominantly reported long-lasting negative treatment effects at 12 months follow-up for functional domains, whereas psychological domains showed near-complete recovery at group level.

CONCLUSIONS

At long-term, various function-related and psychosocial HRQOL domains still are affected in head and neck cancer survivors. The results may serve to better inform patients with regard to specific treatments and highlight HRQOL domains which may potentially be optimized.

Surgical Techniques in Non-Traumatic Midcarpal Instability: Evaluating the Dorsal Capsulodesis and Three-Ligament Tenodesis Technique

BACKGROUND

Surgical management of midcarpal instability (MCI), also referred to as carpal instability nondissociative, remains controversial due to limited evidence on different techniques. This study aimed to assess and compare differences in patient-reported pain, hand and wrist function, patient satisfaction, range of motion, and return to work in patients with non-traumatic MCI who underwent surgical treatment either through dorsal wrist capsulodesis or three-ligament tenodesis (3LT).

METHODS

Patients with MCI and persisting complaints after conservative therapy treated with 3LT or dorsal capsulodesis were included. Patients with posttraumatic instability were excluded. Primary endpoints included the Patient Rated Wrist Evaluation (PRWE) and Satisfaction with Treatment Result Questionnaire at 12 months postoperative. All data were retrospectively analyzed.

RESULTS

A total of 91 patients treated with dorsal capsulodesis and 21 treated with 3LT between December 2011 and December 2019 were included. At twelve months postoperative, both treatment groups reported significant improvements in pain and function scores. However, at three months postoperative, the dorsal capsulodesis group exhibited significantly better outcomes, followed by a greater return to work (72%) compared to the 3LT group (50%). However, the capsulodesis group demonstrated a decreased range of motion at three months which was restored at 12 months postoperative. No significant difference in satisfaction with treatment was observed.

CONCLUSIONS

Both 3LT and dorsal capsulodesis demonstrate promising results for addressing non-traumatic MCI. However, considering the quicker recovery and faster return to work associated with dorsal capsulodesis, we recommend favoring capsulodesis over 3LT when both surgical options are deemed suitable for the patient.

LEVEL OF EVIDENCE

III.

Incision techniques for trigger thumb release: a comparison of outcomes of four types of skin incision

Although trigger thumb release is commonly performed, there is no consensus on the optimal skin incision. This study aimed to compare outcomes of four incision techniques, including V-shaped, oblique, transverse and longitudinal incisions. Outcomes included the Michigan Hand Outcomes Questionnaire, satisfaction with the treatment and postoperative complications. The results of 875 patients who underwent trigger thumb release were assessed. All groups demonstrated improvement in self-reported hand function (range of 10-14 points), pain (25-27 points) and aesthetics (4-7 points) from baseline to 3 months postoperatively with no differences between incision techniques. Of the patients, 76% reported good or excellent satisfaction with the outcome of treatment. Satisfaction and complication rates of the different incision techniques were similar. These findings imply that there is no clear benefit of one type of incision over another for trigger thumb release, suggesting that surgeons may use the technique of their preference.Level of evidence: III.

Phantom Limb Pain and Painful Neuroma After Dysvascular Lower-Extremity Amputation: A Systematic Review and Meta-Analysis

BACKGROUND

Phantom limb pain (PLP) and symptomatic neuroma can be debilitating and significantly impact the quality of life of amputees. However, the prevalence of PLP and symptomatic neuromas in patients following dysvascular lower limb amputation (LLA) has not been reliably established. This systematic review and meta-analysis evaluates the prevalence and incidence of phantom limb pain and symptomatic neuroma after dysvascular LLA.

METHODS

Four databases (Embase, MEDLINE, Cochrane Central, and Web of Science) were searched on October 5th, 2022. Prospective or retrospective observational cohort studies or cross-sectional studies reporting either the prevalence or incidence of phantom limb pain and/or symptomatic neuroma following dysvascular LLA were identified. Two reviewers independently conducted the screening, data extraction, and the risk of bias assessment according to the PRISMA guidelines. To estimate the prevalence of phantom limb pain, a meta-analysis using a random effects model was performed.

RESULTS

Twelve articles were included in the quantitative analysis, including 1924 amputees. A meta-analysis demonstrated that 69% of patients after dysvascular LLA experience phantom limb pain (95% CI 53-86%). The reported pain intensity on a scale from 0-10 in LLA patients ranged between 2.3 ± 1.4 and 5.5 ± .7. A single study reported an incidence of symptomatic neuroma following dysvascular LLA of 5%.

CONCLUSIONS

This meta-analysis demonstrates the high prevalence of phantom limb pain after dysvascular LLA. Given the often prolonged and disabling nature of neuropathic pain and the difficulties managing it, more consideration needs to be given to strategies to prevent it at the time of amputation.

The effectiveness of acellular nerve allografts compared to autografts in animal models: A systematic review and meta-analysis

BACKGROUND

Treatment of nerve injuries proves to be a worldwide clinical challenge. Acellular nerve allografts are suggested to be a promising alternative for bridging a nerve gap to the current gold standard, an autologous nerve graft.

OBJECTIVE

To systematically review the efficacy of the acellular nerve allograft, its difference from the gold standard (the nerve autograft) and to discuss its possible indications.

MATERIAL AND METHODS

PubMed, Embase and Web of Science were systematically searched until the 4th of January 2022. Original peer reviewed paper that presented 1) distinctive data; 2) a clear comparison between not immunologically processed acellular allografts and autologous nerve transfers; 3) was performed in laboratory animals of all species and sex. Meta analyses and subgroup analyses (for graft length and species) were conducted for muscle weight, sciatic function index, ankle angle, nerve conduction velocity, axon count diameter, tetanic contraction and amplitude using a Random effects model. Subgroup analyses were conducted on graft length and species.

RESULTS

Fifty articles were included in this review and all were included in the meta-analyses. An acellular allograft resulted in a significantly lower muscle weight, sciatic function index, ankle angle, nerve conduction velocity, axon count and smaller diameter, tetanic contraction compared to an autologous nerve graft. No difference was found in amplitude between acellular allografts and autologous nerve transfers. Post hoc subgroup analyses of graft length showed a significant reduced muscle weight in long grafts versus small and medium length grafts. All included studies showed a large variance in methodological design.

CONCLUSION

Our review shows that the included studies, investigating the use of acellular allografts, showed a large variance in methodological design and are as a consequence difficult to compare. Nevertheless, our results indicate that treating a nerve gap with an allograft results in an inferior nerve recovery compared to an autograft in seven out of eight outcomes assessed in experimental animals. In addition, based on our preliminary post hoc subgroup analyses we suggest that when an allograft is being used an allograft in short and medium (0-1cm, > 1-2cm) nerve gaps is preferred over an allograft in long (> 2cm) nerve gaps.

Fasciocutaneous and jejunal free flaps for circumferential hypopharyngeal defect reconstruction: A 22-year multicenter cohort study

BACKGROUND

It remains unclear whether a tubed fasciocutaneous or jejunal free flap (FCFF and JFF) is preferable for reconstruction of circumferential pharyngolaryngoesophageal defects.

METHODS

All consecutive patients with circumferential pharyngolaryngoesophageal defects reconstructed with an FCFF or JFF between 2000 and 2022 were included. Outcomes of interest were rates of fistulas, strictures, and donor-site complications.

RESULTS

In total, 112 patients were included (35 FCFFs and 77 JFFs). Fistula and stricture rates were significantly lower following JFF compared to FCFF reconstructions, with 12% versus 34% (p = 0.008) and 29% versus 49% (p = 0.04), respectively. Severe donor-site complications leading to surgical intervention or ICU admittance only occurred after JFF reconstructions (18%, p = 0.007).

CONCLUSIONS

The high fistula and stricture rates in FCFF reconstructions and the rate of severe abdominal complications in JFF reconstructions illustrate inherent procedure-specific advantages and disadvantages. Relative pros and cons should be carefully weighed when tailoring treatments to the individual needs of patients.

Educating Future Generations of Surgeons across Borders: Novel Global Linked Hybrid Live Cadaveric Peripheral Nerve Surgical Training Course

Background

This study aimed to evaluate a novel, multi-site, technology-facilitated education and training course in peripheral nerve surgery. The program was developed to address the training gaps in this specialized field by integrating a structured curriculum, high-fidelity cadaveric dissection, and surgical simulation with real-time expert guidance.

Methods

A collaboration between the Global Nerve Foundation and Esser Masterclass facilitated the program, which was conducted across three international sites. The curriculum was developed by a panel of experienced peripheral nerve surgeons and included both text-based and multimedia resources. Participants' knowledge and skills were assessed using pre- and postcourse questionnaires.

Results

A total of 73 participants from 26 countries enrolled and consented for data usage for research purposes. The professional background was diverse, including hand surgeons, plastic surgeons, orthopedic surgeons, and neurosurgeons. Participants reported significant improvements in knowledge and skills across all covered topics (p < 0.001). The course received a 100% recommendation rate, and 88% confirmed that it met their educational objectives.

Conclusions

This study underscores the potential of technology-enabled, collaborative expert-led training programs in overcoming geographical and logistical barriers, setting a new standard for globally accessible, high-quality surgical training. It highlights the practical and logistical challenges of multi-site training, such as time zone differences and participant fatigue. It also provides practical insights for future medical educational endeavors, particularly those that aim to be comprehensive, international, and technologically facilitated.

Anatomy of the Superficial Radial Nerve and Its Target Nerves for Targeted Muscle Reinnervation: An Anatomical Cadaver Study

BACKGROUND

Targeted muscle reinnervation (TMR) is a surgical procedure for treating symptomatic neuroma, in which the neuroma is removed and the proximal nerve stump is coapted to a donor motor branch innervating a nearby muscle. This study aimed to identify optimal motor targets for TMR of the superficial radial nerve (SRN).

METHODS

Seven cadaveric upper limbs were dissected to describe the course of the SRN in the forearm and motor nerve supply-number, length, diameter, and entry points in muscle of motor branches-for potential recipient muscles.

RESULTS

The radial nerve provided three (three of six) motor branches, two (two of six) motor branches, or one (one of six) motor branch to the brachioradialis muscle, entering the muscle 21.7 ± 17.9 to 10.8 ± 15 mm proximal to the lateral epicondyle. One (one of seven), two (three of seven), three (two of seven), or four (one of seven) motor branches innervated the extensor carpi radialis longus muscle, with entry points 13.9 ± 16.2 to 26.3 ± 14.9 mm distal from the lateral epicondyle. In all specimens, the posterior interosseous nerve gave off one motor branch to the extensor carpi radialis brevis, which divided into two or three secondary branches. The distal anterior interosseus nerve was assessed as a potential recipient for TMR coaptation and had a freely transferable length of 56.4 ± 12.7 mm.

CONCLUSIONS

When considering TMR for neuromas of the SRN in the distal third of the forearm and hand, the distal anterior interosseus nerve is a suitable donor target. For neuromas of the SRN in the proximal two-thirds of the forearm, the motor branches to the extensor carpi radialis longus, extensor carpi radialis brevis, and brachioradialis are potential donor targets.

Treatment Delay in Patients Undergoing Headache Surgery (Nerve Decompression Surgery)

Background

Although headache surgery has been shown to be an effective treatment option for refractory headache disorders, it has not been included as part of the headache disorder management algorithm by non-surgical providers. This study aims to evaluate the delay in surgical management of patients with headache disorders. In addition, a cost comparison analysis between conservative and operative treatment of headache disorders was performed, and the surgical outcomes of headache surgery were reported.

Methods

Among 1112 patients who were screened, 271 (56%) patients underwent headache surgery. Data regarding the onset of headache disorder and pre- and postoperative pain characteristics were prospectively collected. To perform a cost comparison analysis, direct and indirect costs associated with the conservative treatment of headache disorders were calculated.

Results

The median duration between onset of headache disorder symptoms and headache surgery was 20 (8.2-32) years. The annual mean cost of conservative treatment of headache disorders was $49,463.78 ($30,933.87-$66,553.70) per patient. Over the 20-year time period before surgery, the mean cost was $989,275.65 ($618,677.31-$1,331,073.99). In comparison, the mean cost of headache surgery was $11,000. The median pain days per month decreased by 16 (0-25) (p<0.001), the median pain intensity reduced by 4 (2-7) (p<0.001), and the median pain duration decreased by 11 hours (0-22) (p<0.001).

Conclusion

This study shows that patients experience symptoms of headache disorders for an average of 20 years prior to undergoing headache surgery. Surgical treatment not only significantly improves headache pain but also reduces healthcare costs and should be implemented in the management algorithm of headache disorders.

Sensory nerve transfers in the upper limb after peripheral nerve injury: a scoping review

Nerve transfer for motor nerve paralysis is an established technique for treating complex nerve injuries. However, nerve transfer for sensory reconstruction has not been widely used, and published research on this topic is limited compared to motor nerve transfer. The indications and outcomes of nerve transfer for the restoration of sensory function remain unproven. This scoping review examines the indications, outcomes and complications of sensory nerve transfer. In total, 22 studies were included; the major finding is that distal sensory nerve transfers are more successful than proximal ones in succeeding protective sensation. Although the risk of extension of the sensory deficit with donor site loss and morbidity from neuromas remain a barrier to wider adoption, these complications were not reported in the review. Further, the scarcity of studies and small patient series limit the ability to determine sensory nerve transfer success. However, sensory restoration remains an opportunity for surgeons to pursue.Level of evidence: II.

Reconstruction of partial hypopharyngeal defects following total laryngectomy: Pectoralis major myofascial versus myocutaneous flaps

BACKGROUND

To date, few comparative studies exist for partial hypopharyngeal defect reconstruction following total laryngectomy. In the absence of objective evidence from comparative studies, the ideal flap choice remains controversial, leading to heterogeneity in institutional treatment protocols. Comparative studies between different reconstructive techniques are required. Therefore, this study compared postoperative outcomes of pectoralis major myocutaneous (PMMC) and myofascial (PMMF) flaps.

METHODS

A single-center retrospective cohort study was performed between 2000 and 2022, which included all consecutive patients who underwent a PMMC or PMMF flap reconstruction following total laryngectomy and partial hypopharyngectomy. Primary outcomes were suture line leakages (conservative management), fistulas (surgical management), and strictures. Secondary outcomes included flap failure, donor-site morbidity, and the start of oral intake.

RESULTS

In total, 122 patients were included (109 PMMC and 13 PMMF flap reconstructions). The incidence of suture line leakage was significantly higher (p = 0.007) after PMMC flaps (57%) compared with PMMF flaps (15%). Between PMMC and PMMF flaps, fistula (19% vs. 0%) and stricture rates (22% vs. 15%) did not differ significantly. No differences in flap failure, donor-site morbidity, or start of oral intake were observed.

CONCLUSIONS

PMMF flaps have inherent advantages (e.g., reduced bulk, increased pliability) over conventional PMMC flaps and have non-inferior results compared to the latter in terms of postoperative complications. Although the final choice for reconstruction should be patient-tailored, a PMMF flap can be considered a reliable primary choice that is feasible in most patients.

Feasibility of Ultrasound Measurements of Peripheral Sensory Nerves in Head and Neck Area in Healthy Subjects

Background

Current diagnostic methods for nerve compression headaches consist of diagnostic nerve blocks. A less-invasive method that can possibly aid in the diagnosis is ultrasound, by measuring the cross-sectional area (CSA) of the affected nerve. However, this technique has not been validated, and articles evaluating CSA measurements in the asymptomatic population are missing in the current literature. Therefore, the aim of this study was to determine the feasibility of ultrasound measurements of peripheral extracranial nerves in the head and neck area in asymptomatic individuals.

Methods

The sensory nerves of the head and neck in healthy individuals were imaged by ultrasound. The CSA was measured at anatomical determined measurement sites for each nerve. To determine the feasibility of ultrasound measurements, the interrater reliability and the intrarater reliability were determined.

Results

In total, 60 healthy volunteers were included. We were able to image the nerves at nine of 11 measurement sites. The mean CSA of the frontal nerves ranged between 0.80 ± 0.42 mm2 and 1.20 ± 0.43 mm2, the mean CSA of the occipital nerves ranged between 2.90 ± 2.73 mm2 and 3.40 ± 1.91 mm2, and the mean CSA of the temporal nerves ranged between 0.92 ± 0.26 mm2 and 1.40 ± 1.11 mm2. The intrarater and interrater reliability of the CSA measurements was good (ICC: 0.75-0.78).

Conclusions

Ultrasound is a feasible method to evaluate CSA measurements of peripheral extracranial nerves in the head and neck area. Further research should be done to evaluate the use of ultrasound as a diagnostic tool for nerve compression headache.

Outcomes Following Surgery for Common Peroneal Nerve Intraneural Ganglion Cysts: A Case Series and Systematic Review

Background

Intraneural ganglia are a rare cause of common peroneal nerve palsy. Although several treatment modalities exist, surgical intervention is recommended, especially in the setting of neurological dysfunction. We present a case series and systematic review on the clinical outcomes following surgical excision of common peroneal nerve intraneural ganglia.

Methods

We performed a retrospective chart review of all patients who had undergone surgery for common peroneal nerve intraneural ganglia at Queen Elizabeth Hospital in Birmingham, UK, from 2012 to 2022. Demographic and pre- and postoperative findings were collected. A comprehensive literature search of MEDLINE and EMBASE databases was also performed to identify similar studies. Data were subsequently extracted from included studies and qualitatively analyzed.

Results

Five patients at our center underwent procedures to excise intraneural ganglia. There was a male preponderance. Pain, foot drop, and local swelling were the common presenting features. Postoperatively, all patients who completed follow-up demonstrated improved motor function with no documented cyst recurrence. The systematic review identified 6 studies involving 128 patients with intraneural ganglia treated with surgery. Similar findings were reported, with objective and subjective measures of foot and ankle function and symptoms improving after surgical intervention. The recurrence rate varied from 0% to 25%, although most recurrences were extraneural.

Conclusions

Excision of intraneural ganglia is associated with symptomatic relief and functional improvement. Recurrence rates are relatively low and are rarely intraneural.

Patient-Reported Outcomes and Function after Surgical Repair of the Ulnar Collateral Ligament of the Thumb

PURPOSE

The purpose of this study was to report prospectively collected patient-reported outcomes of patients who underwent open thumb ulnar collateral ligament (UCL) repair and to find risk factors associated with poor patient-reported outcomes.

METHODS

Patients undergoing open surgical repair for a complete thumb UCL rupture were included between December 2011 and February 2021. Michigan Hand Outcomes Questionnaire (MHQ) total scores at baseline were compared to MHQ total scores at three and 12 months after surgery. Associations between the 12-month MHQ total score and several variables (i.e., sex, injury to surgery time, K-wire immobilization) were analyzed.

RESULTS

Seventy-six patients were included. From baseline to three and 12 months after surgery, patients improved significantly with a mean MHQ total score of 65 (standard deviation [SD] 15) to 78 (SD 14) and 87 (SD 12), respectively. We did not find any differences in outcomes between patients who underwent surgery in the acute (<3 weeks) setting compared to a delayed setting (<6 months).

CONCLUSIONS

We found that patient-reported outcomes improve significantly at three and 12 months after open surgical repair of the thumb UCL compared to baseline. We did not find an association between injury to surgery time and lower MHQ total scores. This suggests that acute repair for full-thickness UCL tears might not always be necessary.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic II.

Two-, Three-, or Four-Corner Arthrodesis for Midcarpal Osteoarthritis: A Systematic Review and Meta-Analysis

PURPOSE

Several limited midcarpal arthrodeses have been used in the treatment of midcarpal osteoarthritis as part of scapholunate advanced collapse and scaphoid nonunion advanced collapse. There is no consensus on whether two-carpal arthrodesis (2CA), three-carpal arthrodesis (3CA), bicolumnar arthrodesis, or four-carpal arthrodesis (FCA) results in the best outcomes. The objective of this study was to determine whether there is a difference in outcomes in patients undergoing FCA, 3CA, 2CA, or bicolumnar arthrodesis for midcarpal osteoarthritis.

METHODS

A systematic review and meta-analysis were performed in multiple databases following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies reporting the four surgical techniques were included. The primary outcomes were postoperative visual analog scale pain score, the Disabilities of the Arm, Shoulder, and Hand score, and the Mayo Wrist Score. The secondary outcomes were active range of motion, grip strength, and reported complications.

RESULTS

Of 2,270 eligible studies, 80 articles were selected, including a total of 2,166 wrists. The visual analog scale pain scores for both the 2CA and FCA groups reached an adequate pain reduction based on the Patient Acceptable Symptom Scale. The Disabilities of the Arm, Shoulder, and Hand score was also comparable between these two groups. The 2CA group also showed a significantly better active range of motion than the FCA group for both flexion-extension and radioulnar deviation arc. The incidence of nonunion was 6.9% in the FCA group compared with 10.0% in the 2CA group.

CONCLUSIONS

Although the 2CA procedure has a theoretical advantage over the FCA method, the analysis of data showed that generally, these techniques have similar outcomes and complications. Therefore, both (2CA and FCA) are good options for midcarpal osteoarthritis in scapholunate advanced collapse and scaphoid nonunion advanced collapse wrists.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Multiple Compression Syndromes of the Same Upper Extremity: Prevalence, Risk Factors, and Treatment Outcomes of Concomitant Treatment

PURPOSE

Multiple nerve compression syndromes can co-occur. Little is known about this coexistence, especially about risk factors and surgical outcomes. Therefore, this study aimed to describe the prevalence of multiple nerve compression syndromes in the same arm in a surgical cohort and determine risk factors. Additionally, the surgical outcomes of concomitant treatment were studied.

METHODS

The prevalence of surgically treated multiple nerve compression syndromes within one year was assessed using a review of patients' electronic records. Patient characteristics, comorbidities, and baseline scores of the Boston Carpal Tunnel Questionnaire were considered as risk factors. To determine the treatment outcomes of simultaneous treatment, patients who underwent concomitant carpal tunnel release (CTR) and cubital tunnel release (CubTR) were selected. The treatment outcomes were Boston Carpal Tunnel Questionnaire scores at intake and at 3 and 6 months after the surgery, satisfaction 6 months after the surgery, and return to work within the first year.

RESULTS

A total of 7,867 patients underwent at least one nerve decompression between 2011 and 2021. Of these patients, 2.9% underwent multiple decompressions for the same upper extremity within one year. The risk factors for this were severe symptoms, younger age, and smoking. Furthermore, the treatment outcomes of concomitant CTR and CubTR did not differ from those of CubTR alone. The median time to return to work after concomitant treatment was 6 weeks. Patients who underwent CTR or CubTR alone returned to work after 4 weeks.

CONCLUSIONS

Approximately 3% of the patients who underwent surgical treatment for nerve compression syndrome underwent decompression for another nerve within 1 year. Patients who report severe symptoms at intake, are younger, or smoke are at a greater risk. Patients with carpal and cubital tunnel syndrome may benefit from simultaneous decompression. The time to return to work may be less than if they underwent decompressions in separate procedures, whereas their surgical outcomes are comparable with those of CubTR alone.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

[The surgical treatment of peripheral neuromas]

Peripheral neuromas are a prevalent problem following nerve injury or certain surgical interventions like limb amputation. It is important to consider a peripheral neuroma when a patient experiences pain in the innervation area of a peripheral sensory or mixed nerve (branch), especially following trauma or amputation. Adequate recognition of a painful neuroma is crucial to treat patients satisfactorily for their invalidating and chronic symptoms. We want to emphasize that surgical intervention can be an effective and permanent treatment for symptomatic neuromas. The standard surgical treatment is neuroma excision and burying of the nerve stump in adjacent muscle. However, there is a shift towards new and active techniques like Targeted Muscle Reinnervation, of which future comparative research will have to demonstrate whether it is more effective in treating peripheral neuroma pain than conventional surgery.

[The surgical treatment of peripheral neuromas]

Peripheral neuromas are a prevalent problem following nerve injury or certain surgical interventions like limb amputation. It is important to consider a peripheral neuroma when a patient experiences pain in the innervation area of a peripheral sensory or mixed nerve (branch), especially following trauma or amputation. Adequate recognition of a painful neuroma is crucial to treat patients satisfactorily for their invalidating and chronic symptoms. We want to emphasize that surgical intervention can be an effective and permanent treatment for symptomatic neuromas. The standard surgical treatment is neuroma excision and burying of the nerve stump in adjacent muscle. However, there is a shift towards new and active techniques like Targeted Muscle Reinnervation, of which future comparative research will have to demonstrate whether it is more effective in treating peripheral neuroma pain than conventional surgery.

Comparing Patient-Reported Outcomes on Three-Ligament Tenodesis between Partial and Complete Scapholunate Ligament Injuries: A Cohort Study

PURPOSE

Multiple studies report outcomes after 3-ligament tenodesis (3-LT) in treating traumatic scapholunate interosseous ligament injury (SLIL). However, investigators do not differentiate between patients with partial or complete SLIL injury. The relation between the extent of SLIL disruption and surgical outcomes and if this should be considered when treating a patient with SLIL injury remains unknown. We aimed to evaluate differences in patient-rated wrist evaluation (PRWE) scores, satisfaction and return to work between patients with partial or complete chronic traumatic SLIL injury treated with 3 ligament tenodesis at 12 months after surgery.

METHODS

All patients with chronic SLIL injury (partial and complete) who were treated with 3-LT at our clinic and received the same postoperative management between December 2011 and December 2019 were studied. Only patients who had completed the PRWE and return to work questionnaires preoperatively and 12 months after surgery were included. Patients were allocated to the partial (classified as Geissler 2 or 3) or complete SLIL injury group (classified as Geissler 4) by retrospectively assessing wrist arthroscopy reports.

RESULTS

Thirty-nine patients with partial and 90 with complete SLIL injuries were included. At 1-year follow-up, PRWE scores had significantly improved in both groups. When adjusting for clinical baseline characteristics, there was no statistically significant difference between patients with partial or complete SLIL injury. Patients with complete SLIL injury had a 70% higher return to work within the first 12 months after 3-LT; however, satisfaction with the treatment result was similar for both study groups 1 year after surgery.

CONCLUSIONS

Patients with complete and partial traumatic SLIL injury report better PRWE total scores at 12 months after 3-LT, but there was no statistically significant difference between the groups in PRWE scores or satisfaction with the treatment result.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Neuropathic Donor-site Pain Following Radial Forearm Free Flap Harvest: A Multicenter Study on Incidence, Prognostic Factors and Quality of Life

Background The radial forearm free flap (RFFF) is widely used and is considered one of the workhorse flaps in oncologic head and neck reconstructions. However, the potential for significant donor-site morbidity remains a major drawback. Although various donor-site problems have been reported, the incidence of neuropathic pain and possible predicting factors remain unclear. This study aimed to identify the incidence, prognostic factors and impact on quality of life of neuropathic pain following RFFF harvest. Methods In this multicenter, cross-sectional study, 167 patients who underwent a RFFF reconstruction between 2010-2020 were included. Baseline characteristics were collected by medical charts. All patients received questionnaires to measure patient's pain (Doleur Neuropathic 4 and VAS Pain), hand function (Patient Rated Wrist Hand Evaluation) and quality of life (EuroQol 5D). Multiple logistic regression was used to identify prognostic factors associated with outcomes. Results A total of 114 patients (68%) completed the questionnaire. Neuropathic pain was present in 18% of all patients. Donor-site wound problems, mostly tendon exposure, occurred in 32% and was significantly correlated with neuropathic pain (p=0.003). Neuropathic pain was significantly associated with poorer quality of life (p<0.001) and poorer hand function (p<0.001). Conclusion Almost one-fifth of all patients deal with neuropathic pain following RFFF harvest. Neuropathic pain is significantly correlated with poorer hand function and a poorer quality of life. Therefore, future research should focus on analyzing surgical factors such as the management of wound problems and primary denervation to improve hand function and quality of life of these patients.

Prevalence and Risk Factors for Postoperative Complications Following Open A1 Pulley Release for a Trigger Finger or Thumb

PURPOSE

Although A1 pulley release is an effective treatment to reduce pain and improve hand function, complications may occur. More insight into risk factors for complications is essential to improve patient counseling and potentially target modifiable risk factors. This study aimed to identify factors associated with complications following A1 pulley release.

METHODS

Patients completed baseline questionnaires, including patient characteristics, clinical characteristics, and the Michigan Hand outcomes Questionnaire. We retrospectively reviewed medical records to identify complications classified using the International Consortium for Health Outcome Measurement Complications in Hand and Wrist conditions tool. Grade 1 complications comprise treatment with additional hand therapy, splinting, or analgesics, grade 2 treatment with antibiotics or steroid injections, grade 3A minor surgical treatment, grade 3B major surgical treatment, and grade 3C complex regional pain syndrome. Logistic regression analyses were performed to examine the contribution of patient characteristics, clinical characteristics, and patient-reported outcome measurement scores to complications.

RESULTS

Of the included 3,428 patients, 16% incurred a complication. The majority comprised milder grades 1 (6%) and 2 (7%) complications, followed by more severe grades 3B (2%), 3C (0.1%), and 3A (0.1%) complications. A longer symptom duration (standardized odds ratio [SOR], 1.09), ≥3 preoperative steroid injections (SOR, 3.22), a steroid injection within 3 months before surgery (SOR, 2.02), and treatment of the dominant hand (SOR, 1.34), index finger (SOR, 1.65), and middle finger (SOR, 2.01) were associated with a higher complication rate.

CONCLUSION

This study demonstrates that ≥3 preoperative steroid injections and a steroid injection within 3 months before surgery were the most influential factors contributing to complications. These findings can assist clinicians during patient counseling and may guide preoperative treatment. We recommend that clinicians should consider avoiding steroid injections within 3 months before surgery and to be reluctant to perform >2 steroid injections.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic II.

Factors associated with self-reported pain and hand function following surgical A1 pulley release

Surgical A1 pulley release can considerably reduce pain and improve hand function, but individual outcomes are highly variable. This study aimed to identify factors contributing to self-reported pain and hand function 3 months postoperatively. We included 2681 patients who had received surgical treatment for a trigger finger or thumb and who completed the Michigan Hand outcomes Questionnaire (MHQ). Hierarchical linear regression models were used to investigate patient and clinical characteristics associated with postoperative pain and hand function. For both pain and hand function, the most influential factors associated with worse outcomes were worse MHQ scores at baseline (β 0.38 and 0.33, respectively) and ≥3 preoperative steroid injections (β -0.36 and -0.35). These factors indicated that patients with severe preoperative symptoms represent a group with a more advanced disease that is more difficult to treat. These findings can assist clinicians in patient counselling, expectation management and decision-making about the timing of the intervention.Level of evidence: II.

Management of Recurrent Carpal Tunnel Syndrome: Systematic Review and Meta-Analysis

PURPOSE

Few comparisons have been performed between the outcomes of surgical techniques for recurrent carpal tunnel syndrome. Using a meta-analysis, this study aimed to compare the outcomes of different surgical techniques using the Boston Carpal Tunnel Questionnaire (BCTQ) and visual analog scale (VAS) for pain as outcomes.

METHODS

The following categories were used to define the study's inclusion criteria: population, intervention, comparator, outcomes, and study design. Studies were examined by 2 reviewers, and the Preferred Reporting Items for Systematic Review and Meta-Analyses guidelines were followed. The studies were assigned to 1 of the following treatment groups: decompression with or without neurolysis, autologous fat transfer, hypothenar fat pad, pedicled or free flap, and "other." For our primary outcome, we compared improvement using the BCTQ and VAS for pain between the treatment groups. For our secondary outcome, postoperative BCTQ and VAS pain values were compared.

RESULTS

Fourteen studies were included: 5 case series with postoperative data only and 9 pre-post studies without a control group. With regard to our primary outcome, the studies reported an average improvement of 1.2 points (95% confidence interval [CI][1.5, 0.9]) on a scale of 1-5 on the symptoms severity scale (SSS) of the BCTQ, 1.9 points (95% CI [1.37, 0.79]) on a scale of 1-5 on the function severity scale of the BCTQ, and 3.8 points (95% CI [4.9, 2.6]) on a scale of 1-10 on the VAS for pain. We only found significantly lesser improvement in the "other" treatment group than in the hypothenar fat pad group and autologous fat transfer group using the SSS. The hypothenar fat pad group had the best reported postoperative SSS score of 1.75 (95% CI [1.24, 2.25]), function severity scale score of 1.55 (95% CI [1.20, 1.90]), and VAS pain score of 1.45 (95% CI [0.83, 2.07]).

CONCLUSIONS

All the techniques showed clinically important improvements in all the outcomes. We found lesser improvement in the "other" treatment group than in the hypothenar fat pad group and autologous fat transfer group using the SSS. We found that the hypothenar fat pad group had the best reported postoperative values in our secondary analysis.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Perilunate Injury Timing and Treatment Options: A Systematic Review

Introduction  Perilunate injuries are uncommon yet challenging and often missed injuries, representing 7% of all carpal traumas. Two types of injuries can be identified as follows: perilunate dislocations (PLD) and perilunate fracture-dislocations (PLFD). The purpose of this study was to conduct a systematic review and meta-analysis to establish which surgical treatment is superior for patients with perilunate injuries and the significance of delayed treatment. Methods  A total of 2056 articles were screened, and 16 articles were included. Risk of bias for case-control series and case series were assessed through the National Institute of Health study quality assessment tool. Qualitative outcomes of clinical scores for hand function were compared between different time points (acute, < 7 days; delayed 7-45 days; chronic > 45 days), open and closed reduction, and PLD and PLFD. Results  Overall, the clinical outcome scores of patients treated within 7 days are good. The results suggest that closed reduction and internal fixation (CRIF) offers slightly better outcomes than open reduction and internal fixation (ORIF) for PLFD. Patients treated 6 weeks or more after the initial injury seem to have the worst overall outcomes than patients in the acute or delayed setting. The results suggest that patients with chronic PLD have even worse outcomes than patients with chronic PLFD. Conclusions  Timing of surgery is essential for an optimal outcome. When there is a delay of treatment, the outcomes are inferior to those treated acutely. Early referral to centralized treatment units for perilunate injuries would allow for targeted treatment and facilitate research on this difficult wrist injury.

Outcome of Simple Decompression of Primary Cubital Tunnel Syndrome Based on Patient-Reported Outcome Measurements

PURPOSE

To evaluate the patient-reported outcome measures of patients with primary cubital tunnel syndrome and to assess whether they are affected by preoperative symptom severity.

METHODS

Patients who underwent simple decompression for primary cubital tunnel syndrome were selected from a prospectively maintained database. Outcome measurements consisted of the Boston Carpal Tunnel Questionnaire at intake and at 3 and 6 months after surgery. Also, 6 months after surgery, the patients received a question about their satisfaction with the treatment result. To determine a possible influence of preoperative symptom severity on postoperative outcomes, the sample was divided into quartiles based on symptom severity at intake.

RESULTS

One hundred and forty-five patients were included in the final analysis. On average, all patients improved on the Boston Carpal Tunnel Questionnaire. The subgroup of patients with the mildest symptoms at intake did not improve significantly on symptom severity but did improve significantly on their functional status. In addition, the patients with the most severe symptoms at intake did improve on both aspects. Moreover, no difference in satisfaction with treatment result between the severity of symptoms at intake was found.

CONCLUSIONS

The patients with the mildest symptoms at intake may not improve on symptom severity, but they do improve on functional status after simple decompression for cubital tunnel syndrome. In addition, patients with the most severe symptoms at intake do improve on both symptom severity and functional status. Moreover, all patients reported to be equally satisfied with the treatment result, which suggests that satisfaction is not dependent on the symptom severity at intake. Even those patients with both the mildest symptoms before surgery and the least improvement still seem to benefit from simple decompression.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Nerve recovery from treatment with a vascularized nerve graft compared to an autologous non-vascularized nerve graft in animal models: A systematic review and meta-analysis

Background

Treatment of nerve injuries proves to be a worldwide clinical challenge. Vascularized nerve grafts are suggested to be a promising alternative for bridging a nerve gap to the current gold standard, an autologous non-vascularized nerve graft. However, there is no adequate clinical evidence for the beneficial effect of vascularized nerve grafts and they are still disputed in clinical practice.

Objective

To systematically review whether vascularized nerve grafts give a superior nerve recovery compared to non-vascularized nerve autografts regarding histological and electrophysiological outcomes in animal models.

Material and methods

PubMed and Embase were systematically searched. The inclusion criteria were as follows: 1) the study was an original full paper which presented unique data; 2) a clear comparison between a vascularized and a non-vascularized autologous nerve transfer was made; 3) the population study were animals of all genders and ages. A standardized mean difference and 95% confidence intervals for each comparison was calculated to estimate the overall effect. Subgroup analyses were conducted on graft length, species and time frames.

Results

Fourteen articles were included in this review and all were included in the meta-analyses. A vascularized nerve graft resulted in a significantly larger diameter, higher nerve conduction velocity and axonal count compared to an autologous non-vascularized nerve graft. However, during sensitivity analysis the effect on axonal count disappeared. No significant difference was observed in muscle weight.

Conclusion

Treating a nerve gap with a vascularized graft results in superior nerve recovery compared to non-vascularized nerve autografts in terms of axon count, diameter and nerve conduction velocity. No difference in muscle weight was seen. However, this conclusion needs to be taken with some caution due to the inherent limitations of this meta-analysis. We recommend future studies to be performed under conditions more closely resembling human circumstances and to use long nerve defects.

Higher incidences of neuropathic pain and altered sensation following radial forearm free flap: A systematic review

BACKGROUND

The radial forearm free flap (RFFF) has been used extensively for complex tissue defect reconstructions; however, the potential for significant donor-site morbidity remains a major drawback. Despite an abundance of literature on donor-site morbidities, no consensus has been reached on exact incidences of sensory morbidities that vary largely between 0% and 46%. Incidences of neuropathic pain in the donor site following RFFF still lack, even though clinical experience shows it often occurs. Therefore, the purpose of this systematic review was to identify the incidence of neuropathic pain and altered sensation in the hand following harvesting of a RFFF.

METHODS

A systematic search was performed in multiple databases (Embase, Medline, Cochrane, Web of Science, and Google Scholar). Studies from 1990 onwards that reported donor-site morbidities following harvest of the RFFF were included. Analyzed parameters included hand pain, hypoesthesia, cold intolerance, hyperesthesia, neuroma formation, paresthesia, sharp sensation loss, light sensation loss, and defect closure.

RESULTS

Of the 987 selected studies, 51 eligible articles were selected. The mean level of evidence was 3 (SD 0.6). Twenty articles reported pain as a donor-site morbidity, and the mean incidence of pain reported was 23% (SD 7.8). Hypoesthesia was reported by 37 articles and had a mean incidence of 34% (SD 25). Locations of pain and hypoesthesia included, amongst others, the area of the radial sensory nerve and the skin graft area. The mean incidences of cold intolerance and hyperesthesia were 13% (SD 13) and 16% (SD 15), respectively.

CONCLUSION

The results of this systematic review suggest that 23% of all patients are dealing with neuropathic pain in the donor-site following harvest of an RFFF. Future studies should therefore focus on the prognostic factors and preventive measures of neuropathic pain to further improve clinical outcomes of this widely used flap.

Warm Weather and Surgical Site Infections: A Meta-analysis

Seasonal variability, in terms of warm weather, has been demonstrated to be a significant risk factor for surgical site infections (SSIs). However, this remains an underexposed risk factor for SSIs, and many clinicians are not aware of this. Therefore, a systematic review and meta-analysis has been conducted to investigate and quantify this matter.

METHODS

Articles were searched in Embase, Medline Ovid, Web of Science, Cochrane Central, and Google Scholar, and data were extracted from relevant studies. Meta-analysis used random effects models to estimate and compare the pooled odds ratios (OR) and corresponding confidence intervals (CIs) of surgery performed during the warmest period of the year and the colder period of the year.

RESULTS

The systematic review included 20 studies (58,599,475 patients), of which 14 studies (58,441,420 patients) were included for meta-analysis. Various types of surgical procedures across different geographic regions were included. The warmest period of the year was associated with a statistically significant increase in the risk of SSIs (OR 1.39, 95%CI: [1.34-1.45], P < 0.0001). Selection of specific types of surgical procedures (eg, orthopedic or spinal surgery) significantly altered this increased risk.

CONCLUSIONS

The current meta-analysis showed that warm weather seasons are associated with a statistically significant risk increasement of 39% in developing SSIs. This significant risk factor might aid clinicians in preoperative patient information, possible surgical planning adjustment for high risk patients, and potentially specific antibiotic treatments during the warmer weather seasons that could result in decrease of SSIs.

Description and validation of a simple histological nerve tissue scoring system for nerve allografts

BACKGROUND

In nerve allograft development, currently used subjective histological scoring systems to evaluate nerve structure in experimental studies are not uniform and have not been validated. The aim of this study was to describe and validate a simple, fast and inexpensive method to compare structural properties of nerve allografts on a histological level.

MATERIALS AND METHODS

A total of 113 histological sections of rat (sciatic nerves) and human peripheral nerve segments (thoracodorsal and long thoracic nerve for motor and sural for sensory nerve) treated with various decellularization protocols were analyzed. Slides were stained with Hematoxylin & Eosin (H&E), Toluidine Blue and Laminin. A subjective scoring system using a 5-point scale was used to score each nerve section by four independent researchers. For validation of this score both inter- and intra-rater reliability were calculated using the Intraclass Correlation Coefficient (ICC).

RESULTS

Overall, an excellent correlation between the different observers was found for the Toluidine Blue (ICC = 0.919, 95% CI: 0.891-0.941), H&E (ICC = 0.9, 95% CI: 0.865-0.927) and Laminin staining (ICC = 0.897, 95% CI: 0.860-0.926). Intra-rater reliability was good for all three staining techniques (ICC >0.8).

CONCLUSION

This study demonstrates the validity of this simple scoring system to evaluate nerve structure after different processing protocols. All three evaluated staining techniques can reliably be used for both rat and human nerve tissue. We believe this method is suitable to compare different processing techniques to create processed nerve allografts, especially when the average scores of multiple raters are used.

The role of vascularization in nerve regeneration of nerve graft

Vascularization is an important factor in nerve graft survival and function. The specific molecular regulations and patterns of angiogenesis following peripheral nerve injury are in a broad complex of pathways. This review aims to summarize current knowledge on the role of vascularization in nerve regeneration, including the key regulation molecules, and mechanisms and patterns of revascularization after nerve injury. Angiogenesis, the maturation of pre-existing vessels into new areas, is stimulated through angiogenic factors such as vascular endothelial growth factor and precedes the repair of damaged nerves. Vascular endothelial growth factor administration to nerves has demonstrated to increase revascularization after injury in basic science research. In the clinical setting, vascularized nerve grafts could be used in the reconstruction of large segmental peripheral nerve injuries. Vascularized nerve grafts are postulated to accelerate revascularization and enhance nerve regeneration by providing an optimal nutritional environment, especially in scarred beds, and decrease fibroblast infiltration. This could improve functional recovery after nerve grafting, however, conclusive evidence of the superiority of vascularized nerve grafts is lacking in human studies. A well-designed randomized controlled trial comparing vascularized nerve grafts to non-vascularized nerve grafts involving patients with similar injuries, nerve graft repair and follow-up times is necessary to demonstrate the efficacy of vascularized nerve grafts. Due to technical challenges, composite transfer of a nerve graft along with its adipose tissue has been proposed to provide a healthy tissue bed. Basic science research has shown that a vascularized fascial flap containing adipose tissue and a vascular bundle improves revascularization through excreted angiogenic factors, provided by the stem cells in the adipose tissue as well as by the blood supply and environmental support. While it was previously believed that revascularization occurred from both nerve ends, recent studies propose that revascularization occurs primarily from the proximal nerve coaptation. Fascial flaps or vascularized nerve grafts have limited applicability and future directions could lead towards off-the-shelf alternatives to autografting, such as biodegradable nerve scaffolds which include capillary-like networks to enable vascularization and avoid graft necrosis and ischemia.

Comparable functional motor outcomes after repair of peripheral nerve injury with an elastase-processed allograft in a rat sciatic nerve model

BACKGROUND

A bridging nerve autograft is the gold standard for the repair of segmental nerve injury that cannot be repaired directly. However, limited availability and donor site morbidity remain major disadvantages of autografts. Here, a nerve allograft decellularized with elastase was compared with an autograft regarding functional motor outcome in a rat sciatic segmental nerve defect model. Furthermore, the effect of storage on this allograft was studied.

METHODS

Sixty-six Lewis rats (250-300 g) underwent a 10-mm sciatic nerve reconstruction using either a cold- (n = 22) or frozen-stored (n = 22) decellularized nerve allograft or an autograft (n = 22). Sprague-Dawley rats (300-350 g) served as full major histocompatibility complex-mismatched donors. Functional motor outcome was evaluated after 12 and 16 weeks. Ankle angle, compound muscle action potential (CMAP), isometric tetanic force, wet muscle weight, and histomorphometry were tested bilaterally.

RESULTS

For CMAP and isometric tetanic force, no significant differences were observed between groups. In contrast, for ankle angle, histomorphometry and muscle weight, the cold-stored allograft performed comparable to the autograft, while the frozen-stored allograft performed significantly inferior to the autograft. At week 16, ankle angle was 88.0 ± 3.1% in the cold-stored group, 77.4 ± 3.6% in the frozen-stored group, and 74.1 ± 3.1% in the autograft group (P < .001); At week 16, the muscle weight showed a recovery up to 71.1 ± 4.8% in the autograft group, 67.0 ± 6.6% in the cold-stored group, and 64.7 ± 3.7% in the frozen-stored group (P < .05).

CONCLUSIONS

A nerve allograft decellularized with elastase, if stored under the right conditions, results in comparable functional motor outcomes as the gold standard, the autograft.

Bone vascularized composite allotransplantation model in swine tibial defect: Evaluation of surgical angiogenesis and transplant viability

INTRODUCTION

In prior small animal studies, we maintained vascularized bone allotransplant viability without long-term immunotherapy. Instead, an autogenous neoangiogenic circulation is created from implanted vessels, sufficient to maintain bone viability with only 2 weeks immunosupression. Blood flow is maintained despite rejection of the allogeneic vascular pedicle thereafter. We have previously described a large animal (swine) pre-clinical model, reconstructing tibial defects with vascularized tibial allotransplants. In this manuscript, autologous angiogenesis is evaluated in this model and correlated with bone viability.

MATERIALS AND METHODS

Allogeneic tibial segments were transplanted across a major swine leukocyte antigen mismatch. Microvascular repair of the bone VCA pedicle was combined with intraosseous implantation of an autogenous arteriovenous (AV) bundle. The bundle was ligated in group 1 (n = 4), and allowed to perfuse in group 2 (n = 4). Three-drug immunotherapy was given for 2 weeks. At 16 weeks micro-CT angiography quantified neoangiogenic vessel volume. Bone viability, rejection grade, and bone healing were analyzed.

RESULTS

A substantial neoangiogenic circulation developed from the implanted AV-bundle in group 2, with vessel density superior to ligated AV-bundle controls (0.11 ± 0.05 vs. 0.01 ± 0.01, P = .029). Bone allotransplant viability was also significantly enhanced by neoangiogenesis (78.7 ± 4.4% vs. 27.7 ± 5.8%, P = .028) with higher bone healing scores (21.4 ± 2.9 vs. 12.5 ± 3.7, P = .029). Ligated control tibias demonstrated disorganized bone morphology and higher local inflammation (P = .143).

CONCLUSION

Implantation of autogenous AV bundles into vascularized bone allotransplants resulted in the rapid formation of a neoangiogenic autogenous blood supply in a swine tibia model that maintained bone viability, improved bone healing, and minimized rejection.

Surgical Angiogenesis in Porcine Tibial Allotransplantation: A New Large Animal Bone Vascularized Composite Allotransplantation Model

Segmental bone loss resulting from trauma, infection malignancy and congenital anomaly remains a major reconstructive challenge. Current therapeutic options have significant risk of failure and substantial morbidity. Use of bone vascularized composite allotransplantation (VCA) would offer both a close match of resected bone size and shape and the healing and remodeling potential of living bone. At present, life-long drug immunosuppression (IS) is required. Organ toxicity, opportunistic infection and neoplasm risks are of concern to treat such non-lethal indications. We have previously demonstrated that bone and joint VCA viability may be maintained in rats and rabbits without the need of long-term-immunosuppression by implantation of recipient derived vessels within the VCA. It generates an autogenous, neoangiogenic circulation with measurable flow and active bone remodeling, requiring only 2 weeks of IS. As small animals differ from man substantially in anatomy, bone physiology and immunology, we have developed a porcine bone VCA model to evaluate this technique before clinical application is undertaken. Miniature swine are currently widely used for allotransplantation research, given their immunologic, anatomic, physiologic and size similarities to man. Here, we describe a new porcine orthotopic tibial bone VCA model to test the role of autogenous surgical angiogenesis to maintain VCA viability. The model reconstructs segmental tibial bone defects using size- and shape-matched allogeneic tibial bone segments, transplanted across a major swine leukocyte antigen (SLA) mismatch in Yucatan miniature swine. Nutrient vessel repair and implantation of recipient derived autogenous vessels into the medullary canal of allogeneic tibial bone segments is performed in combination with simultaneous short-term IS. This permits a neoangiogenic autogenous circulation to develop from the implanted tissue, maintaining flow through the allogeneic nutrient vessels for a short time. Once established, the new autogenous circulation maintains bone viability following cessation of drug therapy and subsequent nutrient vessel thrombosis.

The effect of full dose composite tissue allotransplantation immunosuppression on allograft motor nerve regeneration in a rat sciatic nerve model

BACKGROUND

The purpose of this study was to identify which triple immunosuppressive protocols, currently used for vascularized composite allotransplantation in the clinic, will have the best effect on motor function recovery following nerve allograft reconstruction.

METHODS

Eighty-eight Lewis rats underwent a 1-cm sciatic nerve allograft transplantation and skin graft from 44 Brown-Norway rats. Group I received 0.9% isotonic saline (control); Group II, 2 mg/kg FK506; Group III, 1 mg/kg FK506 with 15 mg/kg mycophenolate mofetil (MMF); and Group IV, 2 mg/kg FK506 with 30 mg/kg MMF and prednisone. Each group consisted of 11 rats. After 12 weeks, motor function recovery was evaluated with isometric tetanic force, muscle mass, ankle contracture angle, electrophysiology, and nerve histomorphometry. Adequacy of immunosuppression was monitored with the transplanted skin graft. All data are expressed as a percentage of the contralateral side.

RESULTS

Isometric tetanic force showed significantly better functional recovery in all groups treated with immunosuppression compared to control. Within the immunosuppression groups no significant difference was found: 42.1 ± 6.4% (Group I), 56.1 ± 12.4% (Group II), 58.4 ± 10.7% (Group III), and 61.3 ± 11.2% (Group IV). Group IV was superior to all other groups regarding ankle contracture (P < .05) and electrophysiology (P < .001). Skin graft rejection occurred in 41 and 0% (Groups III and IV, respectively).

CONCLUSIONS

FK506 significantly enhanced motor recovery after allograft reconstruction. This effect was comparable between combination treatment (low-dose FK506 and MMF) and triple therapy (high-dose FK506 and MMF plus prednisolone). However, triple therapy was more effective in suppressing skin rejection.

Recipient-derived angiogenesis with short term immunosuppression increases bone remodeling in bone vascularized composite allotransplantation: A pilot study in a swine tibial defect model

Current vascularized composite allotransplantation (VCA) transplantation protocols rely upon life-long immune modulation to maintain tissue perfusion. Alternatively, bone-only VCA viability may be maintained in small animal models using surgical angiogenesis from implanted autogenous vessels to develop a neoangiogenic bone circulation that will not be rejected. This study tests the method's efficacy in a large animal model as a bridge to clinical practice, quantifying the remodeling and mechanical properties of porcine tibial VCAs. A segmental tibial defect was reconstructed in Yucatan miniature swine by transplantation of a matched tibia segment from an immunologically mismatched donor. Microsurgical repair of nutrient vessels was performed in all pigs, with simultaneous intramedullary placement of an autogenous arteriovenous (AV) bundle in Group 2. Group 1 served as a no-angiogenesis control. All received 2 weeks of immunosuppression. After 16 weeks, micro-CT and histomorphometric analyses were used to evaluate healing and remodeling. Axial compression and nanoindentation studies evaluated bone mechanical properties. Micro-CT analysis demonstrated significantly more new bone formation and bone remodeling at the distal allotransplant/recipient junction and on the endosteal surfaces of Group 2 tibias (p = 0.03). Elastic modulus and hardness were not adversely affected by angiogenesis. The combination of 2 weeks of immunosuppression and autogenous AV-bundle implantation within a microsurgically transplanted tibial allotransplant permitted long-term allotransplant survival over the study period of 16 weeks in this large animal model. Angiogenesis increased bone formation and remodeling without adverse mechanical effects. The method may allow future composite-tissue allotransplantation of bone without the risks associated with long-term immunosuppression. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1242-1249, 2017.

Optimizing decellularization techniques to create a new nerve allograft: an in vitro study using rodent nerve segments

OBJECTIVE

Commercially available processed nerve allografts have been shown to be inferior to autografts in previous animal studies. The authors hypothesized that combining different processing and storage techniques will result in improved nerve ultrastructure preservation, lower immunogenicity, and minimized cellular debris. Different processing protocols were evaluated using chemical detergents, enzymes, and irradiation, with the addition the of enzyme elastase, were used. Additionally, the difference between cold and frozen storage was investigated. The goal of this study was to create an optimized nerve allograft.

METHODS

Fifty rat nerves were decellularized with modifications of previous protocols and the addition of elastase. Subsequently, the nerve segments were stored at either 4°C or −80°C. Both processed and fresh control nerves were analyzed with confocal microscopy using immunohistochemical staining on the basal lamina (laminin γ-1), Schwann cells (S100 protein), and immunogenicity using major histocompatibility complex–I (MHCI) staining. Morphology of the ultrastructure and amount of cellular debris were analyzed on cross-sections of the nerves stained with toluidine blue and H & E, and by using electron microscopy.

RESULTS

Nerve ultrastructure was preserved with all decellularization protocols. Storage at −80°C severely altered nerve ultrastructure after any decellularization method. Elastase was found to significantly reduce the immunogenicity and amount of Schwann cells, while maintaining good structural properties.

CONCLUSIONS

Reduced immunogenicity, diminished cellular debris, and the elimination of Schwann cells was observed when elastase was added to the nerve processing while maintaining ultrastructure. Storage at −80°C after the decellularization process heavily damaged the nerve ultrastructure as compared with cold storage. Further in vivo studies are needed to prove the nerve regenerative capacity of these optimized allografts.

The learning rate in three dimensional high definition video assisted microvascular anastomosis in a rat model

Three-dimensional (3D) high definition (HD) video systems are changing microsurgical practice by providing stereoscopic imaging not only for the surgeon and first assistant using the binocular microscope, but also for others involved in the surgery. The purpose of this study was to evaluate the potential to replace the binocular microscope for microarterial anastomoses and assess the rate of learning based on surgeons' experience. Two experienced and two novice microsurgeons performed a total of 88 rat femoral arterial anastomoses: 44 using a 3D HD video device ('Trenion', Carl Zeiss Meditech) and 44, a binocular microscope. We evaluated anastomosis time and modified OSATS scores as well as the subjects' preference for comfort, image adequacy and technical ease. Experienced microsurgeons showed a steep learning curve for anastomosis times with equivalent OSATS scores for both systems. However, prolonged anastomosis times were required when using the novel 3D-HD system rather than direct binocular vision. Comparable learning rates for anastomosis time were demonstrated for novice microsurgeons and modified OSATS scores did not differ between the different viewing technologies. All microsurgeons reported improved comfort for the 3D HD video system but found the image quality of the conventional microscope superior, facilitating technical ease. The present study demonstrates the potential of 3D HD video systems to replace current binocular microscopes, offering qualitatively-equivalent microvascular anastomosis with improved comfort for experienced microsurgeons. However, image quality was rated inferior with the 3D HD system resulting in prolonged anastomosis times. Microsurgical skill acquisition in novice microsurgeons was not influenced by the viewing system used.

Motor Nerve Recovery in a Rabbit Model: Description and Validation of a Noninvasive Ultrasound Technique

PURPOSE

To develop and validate a noninvasive ultrasound technique for the longitudinal analysis of functional recovery after segmental peroneal nerve reconstruction in a rabbit model.

METHODS

Twelve male New Zealand White rabbits underwent a 1-cm peroneal nerve autograft reconstruction. Ultrasound measurements were performed before surgery and at 1, 2, 4, 8, 12, and 16 weeks postoperatively. All rabbits were managed with manual restraint for the ultrasound procedure, avoiding the risks of anesthetics. At 12 and 16 weeks, we evaluated functional recovery using compound muscle action potential, isometric tetanic force measurements, wet muscle weight, and nerve histomorphometry. Data were compared with ultrasound measurements by calculating the Pearson correlation coefficient. We determined intra-rater and inter-rater reliability of the ultrasound measurements.

RESULTS

Ultrasound demonstrated good correlation with isometric tetanic force measurements and wet muscle weight, good correlation with nerve histomorphometry, and moderate correlation with compound muscle action potential. Both intra-rater and inter-rater reliability of the ultrasound technique was excellent.

CONCLUSIONS

Ultrasound analysis of the tibialis anterior muscle provided a reliable method for analysis of functional recovery in a rabbit peroneal nerve reconstruction model. The noninvasive nature allowed for longitudinal follow-up within the same animal and measurement of early recovery without the use of anesthesia.

CLINICAL RELEVANCE

Application of this noninvasive technique can reduce the variability and sample size necessary in peripheral nerve reconstruction studies and may provide an ideal tool for comparative studies in larger animal models.

The effect of stem cells in bridging peripheral nerve defects: a meta-analysis

OBJECT.: For decades the gold standard for reconstructing a large peripheral nerve defect has been, and remains, the nerve autograft. Alternatives to the nerve autograft include biological conduits and vessels. Adding stem cells in the lumen of a nerve conduit has been the subject of multiple studies. The purpose of the present meta-analysis was to summarize animal experimental studies on the effect of stem cells as a luminal additive when reconstructing a peripheral nerve defect with a nerve graft.

METHODS

A literature search of the MEDLINE and Embase databases was performed from inception to April 2012, searching for animal experiments on peripheral nerve reconstruction models in which a nerve conduit was used with and without the support of 3 different types of stem cells. Stem cells were analyzed according to their origin: bone marrow, adipose tissue, and other origins. Included studies had consistent outcome measurements: walking track analysis, muscle mass ratio, and electrophysiology.

RESULTS

Forty-four studies were included in the final analysis. Forest plots of the 3 outcome measurements (walking track analysis, muscle mass ratio, and electrophysiology) showed positive effects of stem cells on the regeneration of peripheral nerves at different time points. Almost all comparisons showed significant differences for all 3 stem cells groups compared with a control group in which stem cells were not used.

CONCLUSIONS

The present report systematically analyzed the different studies that used stem cells as a luminal additive when bridging a large peripheral nerve defect. All 3 different stem cell groups showed a beneficial effect when used in the reconstruction compared with control groups in which stem cells were not used.