The Relationship Between Hemihamate Graft Size and Proximal Interphalangeal Joint Flexion for Reconstruction of Fracture-Dislocations: A Biomechanical Study.

PURPOSE: The purpose of this study was to determine the relationship between hemihamate graft size and proximal interphalangeal (PIP) joint flexion in a biomechanical fracture-dislocation model. METHODS: We simulated middle finger PIP fracture-dislocations in 5 cadaver hands by resecting 50% of the palmar articular surface of the middle phalanx (P2) base. Fluoroscopy was used to confirm dorsal subluxation of the middle phalanx base after resection. A 10-mm osteochondral hamate graft was contoured to reconstruct the volar lip of the middle phalanx and was progressively downsized by 2-mm increments for each trial. A computer-controlled articulator and jig simulated active flexion and extension of the fingers. Maximum PIP flexion was measured at each graft size using fluoroscopy and digital imaging software. Clinically significant flexion block was defined as PIP flexion less than 90°. RESULTS: The actual mean size of the volar defect created was 52% (3.5 mm) of the middle phalanx articular surface, which created instability and dorsal subluxation in all tested fingers. After hemihamate reconstruction, all specimens were stable throughout flexion and extension for all graft sizes. A flexion block of 90° occurred at a mean graft size of 191% of the defect (6.5 mm). With regard to the volar lip of the P2, grafts that projected an average 0.8 mm past the native volar lip position had 98° (range, 84°-107°) maximum PIP flexion. Grafts that projected an average of 3.1 mm past the native volar lip position had 90° (range, 69°-100°) maximum PIP flexion. Linear regression modeling incorporating all of the results predicted flexion block to occur at a graft size as small as 166% of the 50% volar P2 defect. In this model, for every 50% (1.7-mm) increase in graft size relative to the defect, PIP flexion decreased by approximately 6°. CONCLUSIONS: Nonanatomical hemihamate grafts produce a PIP flexion block at extreme sizes, predicted to occur at greater than 166% of a 50% P2 base articular defect in our model. This suggests that relatively large grafts can be used for reconstruction of PIP fracture-dislocations without substantial biomechanical block to PIP flexion. We suggest sizing no larger than 3 mm past the native P2 volar lip position to avoid an important mechanical block to PIP flexion. CLINICAL RELEVANCE: The information from this study helps surgeons understand how large a hemihamate graft can be used for P2 volar base reconstruction before having a negative impact on PIP flexion.

Ulnar Thumb Pulp Reconstruction Using the Anterograde Homodigital Neurovascular Island Flap.

The thumb ulnar pulp is a critical component of key pinch and precision manipulation. Injuries to this area should be reconstructed with robust, sensate tissue that restores bulk and contour. The existing reconstructive options, however, have substantial risks and drawbacks. We describe an anterograde homodigital neurovascular island flap that provides both sensate and durable coverage of the ulnar thumb pulp. The flap uses innervated glabrous tissue, limits donor site morbidity to the thumb and first web space, and does not require microvascular anastomoses or nerve coaptation. The flap has been previously described for nonthumb fingertip injuries, but it has not been applied to the thumb. We discuss several important technical modifications that are essential to raising and insetting this flap in the thumb, review potential pitfalls, and highlight key steps to ensuring judicious intraoperative decision making and success.

Upper extremity transplantation: current concepts and challenges in an emerging field.

Loss of an isolated upper limb is an emotionally and physically devastating event that results in significant impairment. Patients who lose both upper extremities experience profound disability that affects nearly every aspect of their lives. While prosthetics and surgery can eventually provide the single limb amputee with a suitable assisting hand, limited utility, minimal haptic feedback, weight, and discomfort are persistent problems with these techniques that contribute to high rates of prosthetic rejection. Moreover, despite ongoing advances in prosthetic technology, bilateral amputees continue to experience high levels of dependency, disability, and distress. Hand and upper extremity transplantation holds several advantages over prosthetic rehabilitation. The missing limb is replaced with one of similar skin color and size. Sensibility, voluntary motor control, and proprioception are restored to a greater degree, and afford better dexterity and function than prosthetics. The main shortcomings of transplantation include the hazards of immunosuppression, the complications of rejection and its treatment, and high cost. Hand and upper limb transplantation represents the most commonly performed surgery in the growing field of Vascularized Composite Allotransplantation (VCA). As upper limb transplantation and VCA have become more widespread, several important challenges and controversies have emerged. These include: refining indications for transplantation, optimizing immunosuppression, establishing reliable criteria for monitoring, diagnosing, and treating rejection, and standardizing outcome measures. This article will summarize the historical background of hand transplantation and review the current literature and concepts surrounding it.

Free function muscle transfers for upper extremity reconstruction: a review of indications, techniques, and outcomes.

Free functional muscle transfer (FFMT) replaces destroyed, denervated, or resected skeletal muscle units in the upper extremity with functioning skeletal muscle from other locations in the body. Common indications for FFMT include brachial plexus injuries, ischemic contracture, tumor resection, and extensive direct muscle trauma. Recent studies have focused on improving patient outcomes through refinements in muscle flap harvest and inset, donor nerve selection, and postoperative management. In this review, we assess and summarize the current literature on FFMT, with emphasis on etiopathogenesis, diagnosis, treatment, postoperative management, and clinical outcomes.

Does conventional posterior vault remodeling alter endocranial morphology in patients with true lambdoid synostosis?

BACKGROUND: True lambdoid synostosis (TLS) produces a consistent morphology that includes occipital flattening, an ipsilateral occipitomastoid prominence, and a mild contralateral hemifacial deficiency that minimally improves with surgery. Prior studies have demonstrated that dysmorphic middle and posterior cranial fossae contribute to the craniofacial scoliosis characteristic of TLS. We hypothesize that these endocranial features remain after surgery, causing the persistent hemifacial deficiency seen in these patients. METHODS: Three-dimensional anthropometric measurements were made on preoperative and postoperative CT scans of patients with TLS (n = 5). Quantitative analysis was performed on the middle cranial fossa area (MCF), anterior cranial fossa area (ACF), posterior fossa deflection angle (PFA), petrous ridge angle (PRA), temperomandibular joint (TMJ) angle, and external auditory meatus angle. The results were analyzed using a 2-tailed t test. RESULTS: Preoperative CT scans were obtained at a mean age of 1.05 years. Patients underwent posterior vault remodeling at a mean age of 1.33 years. Postoperative CT scans were obtained a mean age of 3.14 years. Following surgery, patients with TLS demonstrated an unchanged PFA (P = 0.76) with deviation toward the affected suture. The ACF remained symmetrical (P = 0.212), and the contralateral MCF remained enlarged relative to the ipsilateral side (P = 0.003). The contralateral middle fossa became more retrodisplaced (P = 0.021). The ipsilateral PRA remained unchanged (P = 0.95). Ear position also remained asymmetrical (P = 0.037). The position of the TMJ was not statistically different between sides before (P = 0.24) or after surgery (P = 0.07). CONCLUSIONS: Traditional cranioplasty effectively restores calvarial shape, but does not significantly alter the dysmorphic features seen in the endocranium of patients with TLS.

The impact of residency and fellowship training on the practice of microsurgery by members of the american society for surgery of the hand.

PURPOSE: The purpose of this study was to assess the microsurgical training background of current members of the American Society for Surgery of the Hand (ASSH) and then determine the impact that prior training had on current microsurgical practice. METHODS: A 174-item anonymous Web-based survey was sent to all active ASSH members. Items addressed prior residency and fellowship training, practice setting, and training, comfort, and practice of specific microsurgical procedures. Data were analyzed using frequency tables, cross-tabulations, χ tests, and other established statistical methods. RESULTS: Surveys were received from 377 of 2019 ASSH members (18.7% response rate). Residency training was in orthopedics (n=249, 66.9%), plastic surgery (n=56, 15.1%), or general surgery (n=55, 14.8%). Fellowship training was in orthopedic (n=242, 65.1%), combined (n=65, 17.5%), and plastic surgery (n=15, 4%) programs. Microsurgical procedures involving nerves were performed by 96.6% of surgeons (n=337), with no significant differences between surgeons trained in plastic surgery versus orthopedic surgery residencies, and no differences between those who had completed orthopedic versus combined fellowships. Of the surgeons completing the survey, 56.1% (n=208) performed general microvascular procedures, 50% (n=179) performed replantations, and 30.6% (n=113) performed free flaps. Hand surgeons who completed plastic surgery residencies were more likely to perform general microvascular procedures, replantations, and free flaps than surgeons trained in orthopedic residencies. When comparing training in orthopedic and combined fellowships, there was no difference in performance of replantations, free flaps, general microvascular surgery, or microsurgical procedures involving nerves. CONCLUSIONS: Training backgrounds have a substantial impact on current microsurgical practice, with residency having the most significant effect. Specifically, hand surgeons trained in plastic surgery residency programs are more likely to perform replantations, free tissue transfer, and general microvascular surgery than those who completed orthopedic residencies. Fellowship training background does not significantly affect microsurgical practice.

The history and evolution of hand transplantation.

Hand transplantation has proven itself to be a viable treatment option for upper extremity reconstruction. It has grown through advancements in several critical areas: microsurgery, transplant immunology, and hand surgery. The field has also benefited from a global effort with active transplant centers in 3 different continents. The early struggles and breakthroughs of hand transplantation's past have shaped and formed its current state. This article traces the events of the modern era of hand transplantation.

Microsurgery of the upper extremity.

In the past 50 years, hand surgeons have made considerable contributions to microsurgery. The unique demands of complex upper extremity care have driven many of the technical and scientific advances of this discipline, including functional muscle transfers, nerve transfers, and composite tissue allotransplantation. The purpose of this article was to review the current applications of microsurgery to the upper extremity.

Reconstruction of complex total parotidectomy defects using the free anterolateral thigh flap: a classification system and algorithm.

BACKGROUND: Composite defects resulting from total parotidectomy present unique reconstructive challenges. This study reviews our experience using the anterolateral thigh (ALT) flap with adjacent fascia and nerve grafts to reconstruct these defects, and establishes a classification system and treatment algorithm that simplifies reconstruction. METHODS: Between July 2005 and November 2009, 22 patients underwent total parotidectomy and immediate reconstruction with the extended ALT flap. Of total, 21 patients had concomitant neck dissection. Defects were classified as follows: Type I, significant soft-tissue loss (n = 4); Type II, significant soft-tissue loss with facial nerve excision (n = 2); Type III, significant soft-tissue loss with resection of surrounding bone(s) (n = 5); and Type IV, significant soft-tissue loss, bone resection, and facial nerve excision (n = 11). Reconstruction procedures included free ALT (n = 9); ALT with fascia lata sling (n = 4); ALT with nerve grafting (n = 5); and ALT, fascia lata sling, and nerve grafting (n = 4). Complications, functional outcome, and patient satisfaction were assessed by chart review and prospective surveys. RESULTS: Fourteen of 22 patients participated in surveys. There was 1 flap loss. Donor site complications included the following: 4 patients (29%) with minor numbness of the lateral thigh skin, and 1 (7%) seroma. There was no leg weakness or infection. Recipient site morbidity included 2 patients (14%) with Frey syndrome, 3 (21%) with delayed wound healing, 5 (36%) with facial numbness, and 5 with mild oral incompetence. Smile asymmetry was present in 7 patients (50%). Ten patients (71%) reported being "very happy" with their appearance. CONCLUSIONS: The ALT flap, used with adjacent nerve and fascia, offers a versatile option for reconstructing complex parotidectomy defects. The procedure involves minimal donor site morbidity, and results in sound functional outcomes and high degrees of patient satisfaction.

Analysis of differences in the cranial base and facial skeleton of patients with lambdoid synostosis and deformational plagiocephaly.

BACKGROUND: Earlier investigations suggest that the morphologic features of patients with lambdoid synostosis include ipsilateral occipital flattening, an ipsilateral mastoid prominence, downward cant of the posterior skull base to the affected side, and contralateral hemifacial deficiency. These features are absent in patients with deformational plagiocephaly. The authors hypothesize that significant differences in craniofacial morphology exist between patients with lambdoid synostosis and those with deformational plagiocephaly. METHODS: Craniometric measurements were performed on patients with unilateral lambdoid synostosis (n = 9) and deformational plagiocephaly (n = 12). Measurements were performed on affected and unaffected sides and included posterior fossa deflection angle, petrous ridge angle, middle cranial fossa and anterior cranial fossa area, temporomandibular joint displacement, and maxillary and mandibular dimensions. Appropriate statistical tests were performed. RESULTS: Statistically significant differences in posterior fossa deflection angle, petrous ridge angle, and middle cranial fossa were found between groups. Lambdoid synostosis patients demonstrated a larger petrous ridge angle (p = 0.0001) and middle cranial fossa (p = 3.37 × 10(-6)) on the unaffected side. Deformational plagiocephaly patients exhibited no discrepancies between sides. The mean posterior fossa deflection angle was 10.55 degrees for the lambdoid synostosis group and 3.59 degrees for the deformational plagiocephaly group (p < 0.0001). All lambdoid synostosis patients had deviation of the posterior cranial fossa toward the affected side. Deformational plagiocephaly patients had variable deflection. All lambdoid synostosis patients demonstrated marked posterior displacement of the contralateral temporomandibular joint. Deformational plagiocephaly patients had either symmetric temporomandibular joint position (75 percent) or slight contralateral posterior displacement (25 percent). Mandibular size was not significantly different between groups. CONCLUSION: Patients with lambdoid synostosis and deformational plagiocephaly manifest significant differences in cranial base morphology, contributing to the phenotypic differences seen in these two groups of patients.