Osseoscopy-Assisted Femoral Head Restoration and Vascularized Graft for Slipped Capital Femoral Epiphysis: A Case Report.

CASE: A 13-year-old obese adolescent boy with hypothyroidism developed left femoral head avascular necrosis with collapse after slipped capital femoral epiphysis. We restored the femoral head congruity with the aid of osseoscopy and vascularized free fibular graft (VFFG). Four years after surgery, the patient had painless hip range of motion and femoral head contour was maintained. CONCLUSION: This case highlights a novel use of an arthroscopic camera inside the femoral head to visualize and debride the area of collapse, fill the cavity with cancellous bone graft, and use a VFFG to restore articular support preventing further deterioration of the hip joint.

Nerve Lesions in Volkmann Ischemic Contracture.

Volkmann ischemic contracture (VIC) is a late sequela of acute compartment syndrome and consists of extensive muscle necrosis, fibrosis, contracture, and variable degrees of neural dysfunction. The outcome depends on successful restoration of muscle and neural function. The timing of surgery is often determined by the development of contractures and is delayed in the interest of observing some spontaneous recovery and infarct maturation. This period of observation may be detrimental to nerve function with gradual formation of scar tissue and worsening constrictive neuropathy. Early intervention appears to be more effective in preventing further nerve damage and restoring protective sensation. In this article, common features of compartment syndrome, frequently seen nerve lesions, and the effect of timing of surgical intervention on the outcome of VIC were reviewed in the light of the current basic and clinical science literature.

Advances in Limb Preservation: From Replantation to Transplantation.

Over the course of the last 60 years, microsurgical techniques, instrumentation, operating microscopes, and suture materials have all been perfected. Microsurgery training became part of the standard curriculum in plastic, orthopedic, and hand surgery programs. Despite those advances, limb replantation and transplantation are still surgical emergencies owing to limits in composite tissue viability under ischemia. Amputated parts, particularly containing large volumes of muscle, have to be revascularized within 4 hours in order to prevent permanent tissue damage. Static cold storage is the current standard to prolong ischemia time with limited success. Our research for the last 7 years has focused on extending ischemia time prior to revascularization. Our long-term goal is to make replantation and transplantation procedures elective. The following essay is the summary of our efforts.

Effect of Static Cold Storage on Skeletal Muscle after Vascularized Composite Tissue Allotransplantation.

BACKGROUND: Prolonged cold ischemia associated with static cold storage (SCS) results in higher incidence of acute and chronic allograft rejection in solid organ transplantations. Deleterious effects of SCS on vascularized composite tissue allograft were studied with limited data on muscle structure and function. The aim of this study is to evaluate the long-term impact of SCS on muscle metabolism, structure, and force generation using a syngeneic rat hindlimb transplantation model. METHODS: Sixty-five male Lewis rats (250 ± 25 g) were distributed into five groups, including naive control, sciatic nerve denervation/repair, immediate transplantation, transplantation following static warm storage for 6 hours at room temperature, and transplantation following SCS for 6 hours at 4°C. Sciatic nerves were repaired in all transplantations. Muscle samples were taken for histology and metabolomics analysis following electromyography and muscle force measurements at 12 weeks after transplantation. RESULTS: All cold-preserved limbs remained viable at 12 weeks, whereas animals receiving limbs preserved in room temperature had no survivors. The SCS transplantation group showed a 73% injury score, significantly higher than groups receiving immediate transplants without cold preservation (50%, p < 0.05). A significant decline in muscle contractile force was also demonstrated in comparison to the immediate transplantation group (p < 0.05). In the SCS group, muscle energy reserves remained relatively well preserved in surviving fibers. CONCLUSION: SCS extends allograft survival but fails to preserve muscle structure and force.

Long-term Effects of Hypothermic Ex Situ Perfusion on Skeletal Muscle Metabolism, Structure, and Force Generation After Transplantation.

BACKGROUND: Hypothermic ex situ perfusion (HESP) systems are used to prolong allograft survival in solid organ transplantations and have been shown to be superior to static cold storage (SCS) methods. However, the effect of this preservation method on limb allograft survival and long-term function has not yet been tested. In this study, we investigated the long-term effects of the HESP on skeletal muscle metabolism, structure, and force generation and compared it with the current standard of preservation. METHODS: Forty male Lewis rats (250 ± 25 g) were divided into 5 groups, including naive control, sciatic nerve transection or repair, immediate transplantation, SCS, and HESP. For the SCS group, limbs were preserved at 4°C for 6 hours. In the HESP group, limbs were continuously perfused with oxygenated histidine-tryptophan-ketoglutarate (HTK) solution at 10-15°C for 6 hours. Hemodynamic and biochemical parameters of perfusion were recorded throughout the experiment. At 12 weeks, electromyography and muscle force measurements (maximum twitch and tetanic forces) were obtained along with muscle samples for histology and metabolomics analysis. RESULTS: Histology demonstrated 48% myocyte injury in the HESP group compared with 49% in immediate transplantation (P = 0.96) and 74% in the SCS groups (P < 0.05). The maximum twitch force measurement revealed a significantly higher force in the HESP group compared with the SCS group (P = 0.029). Essential amino acid levels of the gastrocnemius muscle did not reach significance, with the exception of higher proline levels in the HESP group. CONCLUSIONS: HESP using HTK protects viability of the limb but fails to restore muscle force in the long term.

Single Muscle Fibre Contractility Testing in Rats to Quantify Ischaemic Muscle Damage During Reperfusion Injury.

OBJECTIVES: In this study, the aim was to investigate the potential for single muscle fibre contractility (SMFC) testing to detect the extent of reperfusion injury following various reperfusion periods. The hypothesis was that force generated by muscle fibres will correlate inversely with the extent of reperfusion injury. METHODS: Twenty-four Lewis rats were distributed among five groups. Group 1 served as normal muscle control. In all other groups, femoral artery flow was occluded for four hours. Muscle biopsies were obtained at 0 hour, six hours, day two, and day seven after reperfusion in Groups 2, 3, 4, and 5, respectively. Samples then underwent ultrastructural analysis (H&E stain) and SMFC testing. RESULTS: The maximum isometric force (mN) generated on Days two and seven after reperfusion decreased from baseline by 21% (p < 0.05), and 53% (p < .001), respectively. The specific force (kPa) followed a similar pattern with a 13% decrease at Day two (p > 0.05) and 31% decrease at Day 7 (p < .001). These results correlated inversely with the extent of quantitative injury on histology. CONCLUSIONS: The study demonstrated an inverse relationship between single muscle fibre contractility testing and neutrophil infiltration during the reperfusion phase. Further clinical studies are needed to evaluate its potential in providing prognostic information for patient outcomes.

Intermediate Cuneiform Resurfacing Arthroplasty for Combined Defects of the Sigmoid Notch and the Lunate Fossa of the Distal Radius.

Posttraumatic comminution and bone loss at the sigmoid notch and the lunate fossa of the distal radius result in substantial impairment. Established salvage methods do not meet the physical demands of young patients. Replacement of the articular cartilage is challenging owing to the loss of 2 articular surfaces in different planes and the lack of a defined autogenous source to replace them simultaneously. The use of an intermediate cuneiform osteoarticular autograft to reconstruct the sigmoid notch and the lunate fossa is a new surgical technique that restores joint congruity and stability while allowing early active motion. In this study, we report a cadaver study detailing the anatomy, the surgical technique, and the functional and radiographic outcomes of our index case. Unlike alternative salvage techniques, restoration of the articular surface of the sigmoid notch and the lunate fossa allows early active and stable forearm and radiocarpal joint motion.

Temporary Bridge Plate Fixation of Pilon Fractures of the Proximal Interphalangeal Joint.

Pilon fractures of the proximal interphalangeal (PIP) joint are challenging injuries that can lead to arthritis, limited motion, and pain. Internal fixation is often difficult owing to comminution and inadequate bony support. External fixation requires a compliant patient and may result in pin-track infection, stiffness, and malunion. In this report, I describe a simple surgical technique of immediate bridge plating of the PIP joint with bone grafting followed by plate removal and joint release. This approach maintains the alignment, restores the articular congruity without the risk of pin-track infection, and allows immediate return to activities of daily living until fracture healing is completed.

Development of an Ex-Situ Limb Perfusion System for a Rodent Model.

Ex-situ perfusion (ESP) is a promising method in preserving vascularized composite tissue allografts (VCAs) with potential to widen donor procurement to larger geographic areas. To optimize the method of preservation, we developed a small animal model to conduct biomolecular investigations. Twenty rat hind limbs (18.2 ± 1.3 g) were procured and connected to our custom-made ESP system. Perfusion pressure and flow parameters were measured with hourly blood gas analysis under near-normothermic (30-35˚C) conditions. Perfusate was prepared with swine hemoglobin (6-9 g/dL) and STEEN Solution. After 6 hours of perfusion, gastrocnemius muscles were evaluated for their histology and metabolomic profiling. Following 3 sets of experiments, perfusion was maintained at an average flow of 0.9 ± 0.24 mL/min and resulted in lactate levels of 3.78 ± 1.02 mmol/L. Metabolomic analysis revealed maintained cellular energy stores (total adenylates perfusion 0.698 ± 0.052 versus baseline 0.685 ± 0.091 umols/ug, p = 0.831), and histologic analysis revealed no evidence of barotrauma or myodegeneration. Rat hind limbs were viable after 6 hours of ESP on our miniaturized ESP system. This study is the first to document the ex-situ hind limb perfusion platform on a rodent model. These experimental findings have potential to guide future research to extend the viable duration of VCA preservation.

The Role of Triangular Fibrocartilage Complex in Axial Stability of the Forearm.

Background The triangular fibrocartilage complex (TFCC) provides stability to the wrist and disruption of this complex can result in axial instability which can lead to ulnocarpal abutment. Purpose This article determines the individual contributions of the volar radioulnar ligament (VRUL), dorsal radioulnar ligament (DRUL), and foveal attachment of the TFCC to longitudinal stability of the forearm under axial load. Materials and Methods Eighteen cadaveric specimens were randomly assigned into three groups representing the component of the TFCC to be initially transected: VRUL, DRUL, and foveal attachment. Prior to transection, posterioranterior radiographs of the wrist were obtained at 0, 44.5, and 90 N of axial load. Serial transection of the TFCC components were performed with radiographs obtained at each of the aforementioned loads. Ulnar variance was assessed with two-way repeated measures analysis of variance and paired t -tests. Results Transection of the foveal attachment demonstrated a significant change in ulnar variance of 1.5 and 0.6 mm under 45 and 90 N of load, respectively. At 0 N of load, there was no significant change in ulnar variance between an intact wrist and a wrist with all three ligaments transected; however, a significant change in ulnar variance, 1.0 mm, was observed under 90 N of load. Conclusion The foveal attachment of the TFCC provides the largest contribution to axial stability. Clinical Relevance The TFCC provides axial stability to the wrist and disruption of the TFCC may result in change in ulnar variance observed on an axial loaded wrist radiograph.

The Effect of Axial Loading on Ulnar Variance.

Background Forearm rotation results in change in ulnar variance. Axial loading of the wrist is required to maintain daily activities. Change in ulnar variance during axial loading has not been investigated previously. Purpose To measure the change in ulnar variance on axially loaded wrists. Patients and Methods We examined 21 asymptomatic individuals and 24 patients with unilateral ulnar-sided wrist pain. All patients underwent standard neutral posteroanterior wrist radiographs without load and under axial loading on bilateral wrists. Axial loading was standardized at 18.1 kgf using an analog weight scale. A magnetic resonance (MR) arthrogram was obtained only in patients with ulnar-sided wrist pain. Beighton flexibility score was recorded on healthy volunteers. Change in ulnar variance between 0 and 18.1 kgf was compared for each wrist among all subjects. A correlation was sought between the change in ulnar variance, MR arthrogram findings, and physical examination. Results In individuals without wrist pain, on average, 0.4 mm increase in ulnar variance was measured between 0 and 18.1 kgf. There was no difference between the dominant and nondominant side. No correlation was found with increasing age. In contrast, patients with ulnar-sided wrist pain displayed an average increase of 0.8 mm in ulnar variance. Compared with the contralateral wrist, more than 1 mm increase in ulnar variance was correlated with intra-articular pathologies including dorsoulnar ligament disruption, central triangular fibrocartilage complex (TFCC) perforation, and foveal detachment. Conclusion Compared with contralateral side, more than 1 mm increase in ulnar variance is suggestive of longitudinal instability or TFCC pathology. Level of Evidence Level II, diagnostic.

Clinical Outcomes of Explosion Injuries to the Hand.

PURPOSE: The purpose of this study is to report clinical outcomes in a cohort of 12 patients with explosion injuries to the hand. METHODS: Twelve male patients with a mean age of 42.4 years (SD, 7.2) were examined at a mean of 54 months after sustaining explosion injuries to the hand. All patients underwent primary reconstruction and early soft tissue coverage within 72 hours after their injuries. Total active range of motion and moving 2-point discrimination in each digit were recorded along with hand injury severity score (HISS), disability of the arm, shoulder, and hand (DASH) score, and American Medical Association (AMA) impairment ratings. RESULTS: For digits saved, the average total active motion at final follow-up was 215 degrees (SD, 66.5). Twenty-two digits had 6-mm 2-point discrimination, and 17 digits had 8- to 10-mm 2-point discrimination. Eight of the 12 patients had secondary procedures. We found a strong correlation between initial HISS and DASH scores at final follow-up. There was also a strong correlation between AMA impairment rating and DASH scores. CONCLUSIONS: Early reconstruction provides protective sensation and preserves some function after explosion injuries. Preoperative HISS correlates with the long-term functional outcome as measured by DASH scores. For this group of patients, postinjury AMA impairment ratings also correlate with functional outcomes for the upper extremity.

Proximal Pole Scaphoid Nonunion Reconstruction With 1,2 Intercompartmental Supraretinacular Artery Vascularized Graft and Compression Screw Fixation.

PURPOSE: To review the incidence of union of patients with proximal pole scaphoid fracture nonunions treated using a 1,2 intercompartmental supraretinacular artery (1,2 ICSRA) vascularized graft and a small compression screw. METHODS: This is a retrospective case series of 12 patients. Calculations of the size of the proximal pole fragment relative to the total scaphoid were performed using posteroanterior view scaphoid radiographs with the wrist in ulnar deviation and flat on the cassette. Analyses were repeated 3 times per subject, and the average ratio of proximal pole fragment relative to the entire scaphoid was calculated. We reviewed medical records, radiographs, and computed tomography (CT) scans of these 12 patients. The CT scans that were performed after an average of 12 weeks were ultimately used to confirm union of the scaphoid fractures. One patient was unable to have a CT so was excluded from the final calculation. RESULTS: All 11 (100%) scaphoid fractures that were assessed by CT were found to be healed at the 12-week assessment point. The mean proximal pole fragment size was 18% (range, 7%-27%) of the entire scaphoid. CONCLUSIONS: The 1,2 ICSRA vascularized graft and compression screw was an effective treatment for patients with proximal pole scaphoid fractures. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Effects of Volar Tilt, Wrist Extension, and Plate Position on Contact Between Flexor Pollicis Longus Tendon and Volar Plate.

PURPOSE: Volar plates positioned at, or distal to, the watershed line have been shown to have a higher incidence of attritional rupture of the flexor pollicis longus (FPL). In this study, we aimed to evaluate the effect of wrist extension and volar tilt on the contact between the plate and the FPL tendon in a cadaver model. We hypothesized that, following volar plate application, loss of native volar tilt increases the contact between the FPL and the plate at lower degrees of wrist extension. METHODS: A volar locking plate was applied on 6 fresh-frozen cadavers. To determine the contact between the plate and the FPL tendon, both structures were wrapped with copper wire and circuit conductivity was monitored throughout wrist motion. A lateral wrist radiograph was obtained at each circuit closure, indicating tendon-plate contact. Baseline measurements were obtained with plate positioned at Soong grades 0, 1, and 2. An extra-articular osteotomy was made and contact was recorded at various volar tilt angles (+5°, 0°, -5°, -10°, -15°, and -20°) in 3 different plate positions. A blinded observer measured the degree of wrist extension on all lateral radiographs. Data were analyzed using linear mixed-effects regression model. RESULTS: Plates placed distal to the watershed line had the most contact throughout wrist range of motion. Significantly, less wrist extension was required for contact in wrists with neutral or dorsal tilt and in distally placed volar plates. Volar tilt, wrist extension, and plate position were 3 independent risk factors determining contact between plate and tendon. CONCLUSIONS: Loss of volar tilt, increased wrist extension, and higher Soong grade plate position result in greater contact between wire-wrapped FPL tendon and plate. CLINICAL RELEVANCE: The FPL/plate contact chart generated in this study may be used to assess the risk of rupture in the clinical setting.

Osseoscopy: Direct Visualization to Assist Core Decompression and Debridement of Necrotic Bone Defects.

Free vascularized fibular grafting after core decompression and debridement of necrotic lesions is an effective surgical treatment of avascular necrosis of the femoral head. A technical challenge encountered in performing this procedure is ensuring adequate debridement of necrotic parts while preserving healthy bone. A previously described method accomplishes this indirectly using radioactive contrast media and fluoroscopy, increasing the risk of radiation exposure. We propose a surgical technique using standard arthroscopic equipment to visualize inside the femoral head, facilitating precise and accurate debridement without additional radiation exposure.

Delayed-Onset Digital Ischemia After Local Anesthetic With Epinephrine Injection Requiring Phentolamine Reversal.

The use of low-dose epinephrine in hand surgery has made it possible to perform a wide range of surgical procedures in the office setting. Low-dose epinephrine use is safe, and its vasoconstrictive effects are reversible with phentolamine. In this report, we present late-onset finger ischemia beginning 3 hours after an ipsilateral carpal tunnel and A1 pulley release of the middle finger anesthetized with local anesthetic and low-dose epinephrine (1:100,000). Finger ischemia lasted 14 hours until rescued with phentolamine injection.

Ex Situ Perfusion of Human Limb Allografts for 24 Hours.

BACKGROUND: Vascularized composite allografts, particularly hand and forearm, have limited ischemic tolerance after procurement. In bilateral hand transplantations, this demands a 2 team approach and expedited transfer of the allograft, limiting the recovery to a small geographic area. Ex situ perfusion may be an alternative allograft preservation method to extend allograft survival time. This is a short report of 5 human limbs maintained for 24 hours with ex situ perfusion. METHODS: Upper limbs were procured from brain-dead organ donors. Following recovery, the brachial artery was cannulated and flushed with 10 000 U of heparin. The limb was then attached to a custom-made, near-normothermic (30-33°C) ex situ perfusion system composed of a pump, reservoir, and oxygenator. Perfusate was plasma-based with a hemoglobin concentration of 4 to 6 g/dL. RESULTS: Average warm ischemia time was 76 minutes. Perfusion was maintained at an average systolic pressure of 93 ± 2 mm Hg, flow 310 ± 20 mL/min, and vascular resistance 153 ± 16 mm Hg/L per minute. Average oxygen consumption was 1.1 ± 0.2 mL/kg per minute. Neuromuscular electrical stimulation continually displayed contraction until the end of perfusion, and histology showed no myocyte injury. CONCLUSIONS: Human limb allografts appeared viable after 24 hours of near-normothermic ex situ perfusion. Although these results are early and need validation with transplantation, this technology has promise for extending allograft storage times.

Elbow Dislocations in Contact Sports.

Elbow dislocations are more common in athletes than in the general population. Simple elbow dislocations should be managed with early range of motion and early return to sport, even with high-level contact athletes. Patients with instability on examination or with complex elbow dislocations may require surgical intervention. Overall, the outcomes after simple elbow dislocations are excellent and athletes should be able to return to play without significant limitations.

Pollicization of the Second Metacarpal Based on Dorsal Metacarpal Arteries.

Blood supply to the index finger is maintained through volar (palmar arch) and dorsal (intermetacarpal arteries) vascular networks. In traditional index finger pollicization, blood supply is maintained on the volar palmar arch. In case of index finger loss at the metacarpophalangeal joint, remaining length of the second metacarpal is often not used for pollicization because the arc of rotation is limited on digital arteries. In this report, we present a surgical technique for the transfer of the index metacarpal to the thumb on the dorsal vascular network. This method adds no further morbidity and can be used as an alternative method of thumb reconstruction in cases in which the thumb and index fingers are amputated.

The Effect of Ex Situ Perfusion in a Swine Limb Vascularized Composite Tissue Allograft on Survival up to 24 Hours.

PURPOSE: To test the potential for the ex situ limb perfusion system to prolong limb allograft survival up to 24 hours. METHODS: We used 20 swine for the study. In group 1 (control), 4 limbs were perfused with heparin solution and preserved at 4°C for 6 hours. In group 2, 4 limbs were perfused with autologous blood at 27°C to 32°C for 24 hours. In both groups, limbs were transplanted orthotopically to recipients and monitored for 12 hours. In addition to perfusion parameters, we recorded perfusate gases and electrolytes (pH, pCO2, pO2, O2 saturation, Na, K, Cl, Ca, HCO3, glucose, and lactate) and obtained functional electrostimulation hourly throughout the experiment. Histology samples were obtained for TUNEL staining and single-muscle fiber contractility testing. RESULTS: In both groups, hemodynamic variables of circulation remained stable throughout the experiment. Neuromuscular electrical stimulation remained intact until the end of reperfusion in group 2 vs no response in group 1. In group 2, a gradual increase in lactate levels during pump perfusion returned to normal after transplantation. Compared with the contralateral limb in group 2, single-muscle fiber contractility testing showed no significant difference at the end of the experiment. CONCLUSIONS: We demonstrated extended limb survival up to 24 hours using normothermic pulsatile perfusion and autologous blood. CLINICAL RELEVANCE: Successful prolongation of limb survival using ex situ perfusion methods provides with more time for revascularization of an extremity.