Cameron Cox

Key Clinical Message: Traumatic brain injuries have the potential to cause the development of long‐term complications. We aim to show that the use of flexor tenotomies in the treatment of flexion contractures following traumatic brain injury is a viable solution.

Peripheral nerve injuries (PNIs) often present with variable symptoms, making them difficult to diagnose, treat, and monitor. When neurologic compromise is inadequately assessed, suboptimal treatment decisions can result in lasting functional deficits. There are many available tools for evaluating pain and functional status of peripheral nerves. However, the literature lacks a detailed, comprehensive view of the data comparing the clinical utility of these modalities, and there is no consensus on the optimal algorithm for sensory and pain assessment in PNIs. We performed a systematic review of the literature focused on clinical data, evaluating pain and sensory assessment methods in peripheral nerves. We searched through multiple databases, including PubMed/Medline, Embase, and Google Scholar, to identify studies that assessed assessment tools and explored their advantages and disadvantages. A total of 66 studies were selected that assessed various tools used to assess patient's pain and sensory recovery after a PNI. This review may serve as a guide to select the most appropriate assessment tools for monitoring nerve pain and/or sensory function both pre- and postoperatively. As the surgeons work to improve treatments for PNI and dysfunction, identifying the most appropriate existing measures of success and future directions for improved algorithms could lead to improved patient outcomes.

Introduction: The extracellular matrix (ECM) plays an integral role in wound healing. It provides both structure and growth factors that allow for the organised cell proliferation. Large or complex tissue defects may compromise host ECM, creating an environment that is unfavourable for the recovery of anatomical function and appearance. Acellular dermal matrices (ADMs) have been developed from a variety of sources, including human (HADM), porcine (PADM) and bovine (BADM), with multiple different processing protocols. The objective of this report is to provide an overview of current literature assessing the clinical utility of ADMs across a broad spectrum of applications. Methods: PubMed, MEDLINE, EMBASE, Scopus, Cochrane and Web of Science were searched using keywords ‘acellular dermal matrix’, ‘acellular dermal matrices’ and brand names for commercially available ADMs. Our search was limited to English language articles published from 1999 to 2020 and focused on clinical data. Results: A total of 2443 records underwent screening. After removing non-clinical studies and correspondence, 222 were assessed for eligibility. Of these, 170 were included in our synthesis of the literature. While the earliest ADMs were used in severe burn injuries, usage has expanded to a number of surgical subspecialties and procedures, including orthopaedic surgery (e.g. tendon and ligament reconstructions), otolaryngology, oral surgery (e.g. treating gingival recession), abdominal wall surgery (e.g. hernia repair), plastic surgery (e.g. breast reconstruction and penile augmentation), and chronic wounds (e.g. diabetic ulcers). Conclusion: Our understanding of ADM’s clinical utility continues to evolve. More research is needed to determine which ADM has the best outcomes for each clinical scenario. Lay Summary: Large or complex wounds present unique reconstructive and healing challenges. In normal healing, the extracellular matrix (ECM) provides both structural and growth factors that allow tissue to regenerate in an organised fashion to close the wound. In difficult or large soft-tissue defects, however, the ECM is often compromised. Acellular dermal matrix (ADM) products have been developed to mimic the benefits of host ECM, allowing for improved outcomes in a variety of clinical scenarios. This review summarises the current clinical evidence regarding commercially available ADMs in a wide variety of clinical contexts.

Background: Scar formation is a normal part of the proliferative phase in wound healing where collagen is remodelled to better approximate normal skin. When collagen is not effectively redistributed, excessive scarring may occur. Recently, CO₂ laser has emerged as an adjunct in improving scar quality via remodelling and redistribution of dermal collagen fibres. Due to the paucity of literature related to its use in the hands and upper extremities, we created a study to examine its effects on hypertrophic scars focused on the hands and upper extremities. Methods: Patients treated with CO₂ laser for hypertrophic scars of the hand and upper extremity were included. The Vancouver Scar Scale (VSS) and Patient and Observer Scar Assessment Scale (POSAS) were used to assess the progression of scar quality. Unpaired t-tests were performed to determine statistical difference between pre- and post-treatment scores on each scale. Pearson correlation coefficients were used to understand the relationship between number of treatments and scar quality. Results: Of the 90 patients enrolled, 54 patients completed serial scar assessment forms. All patient and observer-reported POSAS domains showed improvement ( P < 0.05) apart from Itching. All VSS domains showed improvement ( P < 0.05). There was moderate correlation between overall patient-reported opinion of scar quality and Discoloration, Stiffness and Thickness, and strong correlation between overall patient opinion and Irregularity (r = 0.715). All observer-reported domains were strongly correlated (r = 7.56–8.74) with overall observer opinion of scar quality. Conclusion: The results of this study may further substantiate CO₂ laser as a treatment modality for excessive scarring in a variety of surgical subspecialties. Lay Summary: Complex trauma and burns that impact the skin sometimes result in abnormal healing of the skin called, “hypertrophic scarring”. In our study we assessed how using focused CO₂ laser therapy impacts patients and health care provider assessment of wound progression. Our results were based upon patient reported and healthcare provider observations based upon two standardized forms the Vancouver Scar Scale (VSS) and the Patient and Observer Scar Assessment Scale (POSAS). What we found is that after CO₂ Laser Therapy, our 64 patients with 77 treated scars received on average almost 3 treatments and these treatments helped them with physical function and improved aesthetic appearance of their scars. The health care providers also found that the treatments improved functional and aesthetic end points. Overall, our study helps substantiate the body of evidence that using CO₂ laser therapy improves aesthetics and function of hypertrophic scars in the upper extremity.

Objective: Activities that require increased load bearing are known to cause bony hypertrophy. This phenomenon has been documented in the dominant arm of athletes in sports requiring significant utilization of a single limb. The literature addressing this effect in rodeo athletes, however, is minimal. Studies evaluating rodeo athletes are primarily focused on acute injury management rather than chronic symptoms resulting from changes in bone and soft tissue. We designed a study to evaluate bony hypertrophy in athletes without acute injury. Method: Rodeo bareback riders presented with frequent pain in their grip arm, no radiographic evidence of injury, and clinical signs of peripheral nerve compression. Anteroposterior and lateral X-rays taken for initial evaluation in 17 bareback rodeo athletes were retrospectively reviewed. The diameter of bilateral ulnas was measured at its longitudinal midpoint. Ratio of Ulnar Diameters (grip arm/free arm) and Percentage Diameter Difference were calculated. An independent samples t-test was used to assess differences in diameters of grip and non-grip arms. Result: The mean ulnar diameter was 18.4 ± 3.5 in the grip arm and 16.6 ± 3.5 in the non-grip arm ( p < 0.001). The mean ratio of grip to free arm ulnar diameter was 1.42 ± 0.21 (range = 1.05–1.92). The mean diameter percent difference measured 42.3% (range = 4.7%–92.0%), and the grip arm was observed to have a greater ulnar diameter compared to the non-grip arm. Conclusion: There are significant anatomic differences in the grip arm of bareback rodeo athletes compared to the contralateral arm. In cases of persistent pain in the grip arm and no evidence of acute injury, these differences may be relevant to pain symptoms and should be considered as part of the assessment and treatment algorithm.

Few multifocal hand chondrosarcomas have been reported. To our knowledge, this report is the first to describe multifocal hand chondrosarcoma in a patient with no evidence of prior enchondroma, Ollier's disease, or Maffucci syndrome.

When the metacarpal bones sustain severe osseous injury requiring reconstruction, functional recovery relies on the precise distribution of tension throughout full range of motion. While the small scale of hand structures compounds the effects of altering normal anatomy, literature lacks consensus recommendations for the acceptable degree of length alteration and/or appropriate methods of length estimation in reconstructive procedures. Length asymmetry has been reported in human metacarpal bones; however, studies assessing this phenomenon in living subjects with attention to functional implications or length prediction are lacking. Hand X-rays were obtained for 34 patients aged 25–80 without history of metacarpal trauma, joint degeneration, or pathologic bone metabolism. A scaled bivariate model predicted metacarpal length using an ipsilateral paired metacarpal and matching contralateral ratio: Estimate_Dx_R = Median_Dy_R * (Median_Dx_L/Median_Dy_L). A second set of predictions used the contralateral metacarpal as a control. Pearson correlation coefficients, paired t-tests, and chi-square tests evaluated the symmetry between bilateral metacarpal lengths and paired metacarpal ratios as well as the accuracy of each predictive method. The contralateral control and target metacarpal differed significantly in digits 1, 2, 3, and 5. No significant difference in matched metacarpal ratios of the right and left hands was found. For all digits except 5D, bivariate model predictions generated were more strongly correlated with actual target length. Chi-square tests did not detect a significant difference in predictive value of the two models. The scaled bivariate model we describe may be useful and economic in generating accurate length estimates of metacarpals for reconstructive procedures.

Implant failure leading to revision total joint arthroplasty can occur through a variety of different mechanisms which are typically associated with a soft tissue response adjacent to the implant that provide insight into the underlying etiology of implant failure. The objective of this study was to elucidate mechanisms of implant failure as they relate to histological classification and findings of adjacent periprosthetic tissue. Histological analysis of soft tissue adjacent to the implant was performed in 99 patients with an average age of 64 years old and grouped into four categories based on the study conducted by Morawietz et al.: Modes of failure were categorized into five groupings based on the study conducted by Callies et al.: Instability (N = 35), Aseptic Loosening (N = 24), Hardware and/or Mechanical Failure (N = 15), Septic (N = 13), and Other failures (N = 12). We calculated odds ratios and conducted regression analysis to assess the relationship between modes of failure and histological findings as well as modes of failure and comorbidities. Hardware/mechanical failure was independently correlated with histological findings of anucleate protein debris, histiocytes, Staphylococcus epidermidis, and synovitis. Furthermore, hardware/mechanical failure was independently correlated with osteosarcoma as a co-morbidity. Septic failure was associated with histological findings of Enterococcus, granulation tissue, and tissue necrosis as well as comorbidities of Crohn’s disease, deep venous thrombosis, lung disease, and rheumatoid arthritis. Infection was 5.8 times more likely to be associated with Type II histology. Aseptic loosening was associated with histologic findings of synovitis. Our findings support the existing literature on periprosthetic tissue analysis in revision total joint arthroplasty which may improve surgeon understanding of the patholophysiological mechanisms that contribute to implant failure and revision surgery.

Treatment of patients with traumatic axonotmesis presents challenges. Processed human umbilical cord membrane has been recently developed with improved handling and resorption time compared to other amniotic membrane wraps, and may be beneficial in nerve reconstruction. This study evaluates postoperative outcomes after traumatic peripheral nerve injury after placement of commercially available processed human umbilical cord membrane. We performed a prospective, single-center pilot study of patients undergoing multi-level surgical reconstruction for exposed, non-transected peripheral nerve. Functional outcomes including pain, range of motion, pinch and grip strength, and the QuickDASH and SF-36 patient-reported outcome measures were recorded, when possible, at the 1-week and 3, 6, and 9 months postop visit. One-tailed paired t-tests were performed to evaluate outcome improvement at final follow-up. Twenty patients had processed human umbilical cord membrane placement without surgical complications. Mean follow-up was 7.5 months (range: 3–10 months) and mean age was 39 years (range: 15–65). Twelve (67%) patients were male, and the majority of placement sites were in the upper extremity (85%). Mean preoperative visual analog scale pain score was significantly reduced at most recent follow-up, as were QuickDASH scores. All patients had improved functional outcomes at the 9-month follow-up, and SF-36 outcomes at 9 months showed improvement across all dimensions. This study indicates that processed human umbilical cord membrane may be a useful adjunct in nerve surgery with noted improvements in postoperative function, pain, and patient-reported outcome measures. Future studies are needed to assess long-term outcomes after traumatic nerve injury treated with processed human umbilical cord membrane.