Dorsal Hook Plating of Patella Fractures with Immediate Range of Motion Results in Reliable Fixation, Low Implant Removal Rates, and Satisfactory Clinical Outcomes.

OBJECTIVES: To evaluate radiographic and clinical patient reported clinical outcomes following dorsal hook plating of displaced patella fractures with permittance of immediate post-operative active closed chain range of motion. DESIGN: Retrospective review of prospectively collected data. SETTING: Urban Academic Level 1 Trauma Center. PATIENT SELECTION CRITERIA: Adult patients with displaced patella fractures (OTA/AO 34C1-3) who underwent dorsal plating with immediate range of motion between 2018-2023. OUTCOME MEASURES AND COMPARISONS: Numerical Rating Scale for Pain, Knee Outcome Score (KOS-ADL), Tegner-Lysholm Score, radiographic union, and wound complications were collected. RESULTS: 61 patients were included (47 female) with an average age of 63 years (SD 14.7, range 22-86 years). The mean BMI was 24.2 (SD 3.6, range 16.6-33.3). There were thirteen 34-C2 and forty-eight 34-C3 fractures. All but 2 patients (96.7%) achieved bony union after the index procedure. 89% (n=54) of patients completed outcome surveys with at least 6 months follow-up. Six patients (9.8%) underwent removal of plate implant at a mean of 15.1 months post-operatively. The mean KOS-ADL score was 91.4, the mean Tegner-Lysholm score was 78.1, and the mean NRS was 2.7. CONCLUSION: Dorsal hook plating offers secure fixation to allow early range of motion, reliable fixation with low non-union and implant failure rates, low implant removal rates, and satisfactory patient reported outcomes. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Distal Tibia Apex Posterior Angulation: A Normal Anatomic Variant Related to Hindfoot Alignment With Side-to-Side Symmetry.

OBJECTIVES: The sagittal plane of the distal tibia has not been well-described. This study sought to characterize sagittal plane morphology, determine symmetry from side to side, and identify differences based on hindfoot alignment. METHODS: One hundred twelve bilateral lateral weight-bearing ankle radiographs were retrospectively evaluated (224 ankles). Hindfoot alignment was classified as neutral, planus, or cavus using the Meary angle. The angle between the diaphyseal and distal tibia axes was measured, and the apex location relative to the plafond was recorded. RESULTS: A mean distal tibia apex posterior angulation (DTAPA) of 2.0° (range -2° to 7°, SD = 2.06°) was located 8.0 cm proximal to the plafond. No difference was observed from side to side in DTAPA magnitude (P = 0.36) or location (P = 0.90). Planus alignment was associated with a significantly greater DTAPA (3.05°) as compared with neutral (1.89°) (P = 0.002) and cavus (1.25°) (P < 0.001) alignment. CONCLUSION: The distal tibia has an apex posterior angulation, suggesting that the true anatomic axis of the tibia terminates just posterior to the plafond center. Hindfoot alignment is related to distal tibia morphology. DTAPA symmetry indicates that contralateral imaging can be used to guide reconstruction of patient-specific anatomy and alignment. Knowledge of the DTAPA may help mitigate sagittal malalignment during distal tibia fracture surgery.

Krackow Suture Technique Effect on Patella Tendon Vascularity: Quantitative MRI Analysis.

OBJECTIVES: To assess the effects of Krackow suture technique on the vascularity of the patellar tendon. METHODS: Six fresh-frozen matched pair cadaveric knee specimens were used. The superficial femoral arteries were cannulated in all knees. The experimental knee underwent an anterior approach, patellar tendon transection from the inferior pole of the patella, 4-strand Krackow stitch placement, patellar tendon repair via 3-bone tunnels, and standard skin closure. The control knee underwent the identical procedure without Krackow stitching. All specimens then underwent precontrast and postcontrast enhanced quantitative magnetic resonance imaging assessment (with gadolinium-based contrast agent). Region of interest analysis was performed to assess for variation in signal enhancement between the experimental and control limbs in various patellar tendon regions and subregions. Latex infusion and anatomical dissection were performed to further evaluate vessel integrity and assess extrinsic vascularity. RESULTS: Quantitative magnetic resonance imaging analysis demonstrated no statistically significant difference in overall arterial contributions. A small but nonsignificant decrease of 7.5% (SD ± 7.1%) in arterial contributions to the entire tendon was observed. Small nonstatistically significant regional decreases throughout the tendon were also detected. In the regional analysis, the largest to smallest decreases in arterial contributions after suture placement were found in the inferomedial, superolateral, lateral, and inferior tendon subregions. In the anatomical dissection, nutrient branches were seen dorsally and posteroinferiorly. CONCLUSION: The vascularity of the patellar tendon was not significantly affected by Krackow suture placement. Analysis demonstrated small and not statistically significant decreases in arterial contributions, suggesting this technique does not significantly compromise arterial perfusion.

Apex posterior angulation of the humerus: A characterization of normal sagittal plane anatomy with implications for surgical fixation.

INTRODUCTION: An understanding of the sagittal plane morphology of the humerus is relevant during surgical fixation of humeral fractures but is not well described in the literature. The purpose of this study was to better characterize the native sagittal plane morphology of the humerus. MATERIALS AND METHODS: 170 patients with uninjured full length lateral humerus radiographs were retrospectively evaluated. The angle between the proximal humeral diaphyseal axis and the distal humeral diaphyseal axis was identified and measured. The proximal axis was defined by two points equidistant from the anterior and posterior cortex 10 mm and 100 mm distal to the metaphyseal flare, and the distal axis by two points at 10 mm and 50 mm proximal to the capitellum/trochlea. The relative location of the center of rotation of angulation (CORA) was calculated as a percentage of humeral length. RESULTS: 114 radiographs were included in the analysis (66 right humeri, 48 left humeri). The average apex posterior angulation was 6.5 +/- 2.9°. The CORA occurred at an average of 80% (SD+/-13%) of the length of the humerus (proximal to distal). Total humeral length and absolute distance to CORA were greater in males compared to females (364 ± 50 mm versus 326 ± 30 mm; p<0.001; 290 ± 68 mm versus 260 ± 48 mm; p=0.003), but there were no significant sex differences with respect to magnitude of the apex posterior angulation (p=0.077) or location of CORA as a percentage of total humeral length (p=0.916). There were no statistically significant associations between age and total humeral length (p=0.056), distance to CORA (p=0.130), location of CORA as percentage of total humeral length (p=0.753), or magnitude of angulation (p=0.075). CONCLUSION: An apex posterior bow consistently exists in the distal one-quarter of the humerus that is consistent across ages and between sexes. This normal anatomic bow is important to recognize to avoid an extension malreduction and has implications for implant fit and contouring.

Operative treatment of nonunions in the elderly: Clinical and radiographic outcomes in patients at minimum 75 years of age.

BACKGROUND: Limited information exists on nonunion treatment in the elderly. This retrospective study evaluates whether results of operative treatment of nonunion of the humerus or femur in patients aged ≥ 75 years are comparable to those in younger patients. METHODS: We identified patients age ≥ 75 years with a nonunion of humerus or femur treated with open reduction and internal fixation. The Non-Union Scoring System was calculated. Complications, clinical outcome, and radiographic findings were assessed. Primary endpoint was nonunion healing. A literature review compared time to healing of humeral and femoral nonunion in younger populations. RESULTS: We identified 45 patients treated for a nonunion of humerus or femur with > 12 months follow-up. Median age was 79 years (range 75-96). Median time to presentation was 12 months (range 4-127) after injury, median number of prior surgeries was 1 (range 0-4). Union rate was 100%, with median time to union 6 months (range 2-42). Six patients underwent revision for persistent nonunion and healed without further complications. CONCLUSIONS: Using a protocol of debridement, alignment, compression, stable fixation, bone grafting and early motion, patients aged 75 years or older can reliably achieve healing when faced with a nonunion of the humerus or femur. LEVEL OF EVIDENCE: IV.

Vascularity of the early post-natal human distal femoral chondroepiphysis: Quantitative MRI analysis.

Purpose: Injury to or abnormality of developing distal femoral chondroepiphysis blood supply has been implicated in osteochondritis dissecans development. Progressive decrease in epiphyseal cartilage blood supply occurs in normal development; however, based on animal studies, it is hypothesized that there is greater decrease in regions more prone to osteochondritis dissecans lesions. We aimed to quantify differential regional perfusion of the immature distal femoral chondroepiphysis. We hypothesized there is decreased perfusion in the lateral aspect of the medial femoral condyle, the classic osteochondritis dissecans lesion location. Methods: Five fresh-frozen human cadaveric knees (0-6 months old) were utilized. The superficial femoral artery was cannulated proximally and contrast-enhanced magnetic resonance imaging performed using a previously reported protocol for quantifying osseous and soft tissue perfusion. Regions of interest were defined, and signal enhancement changes between pre- and post-contrast images, normalized to background muscle, were compared. Results: When comparing average normalized post-contrast signal enhancement of whole condyles, as well as distal, posterior, and inner (toward the notch) aspects of the medial and lateral condyles, no significant perfusion differences between condyles were found. In the medial condyle, no significant perfusion difference was found between the medial and lateral aspects. Conclusion: We quantified immature distal femoral chondroepiphysis regional vascularity in the early post-natal knee. In specimens aged 0-6 months, no distinct watershed region was detected. Despite possible limitations, given small sample size, as well as resolution of magnetic resonance imaging and analysis, our results suggest the hypothesized vascular abnormality predisposing osteochondritis dissecans either does not occur universally or occurs after this developmental age.

Differential regional perfusion of the human anterior cruciate ligament: quantitative magnetic resonance imaging assessment.

PURPOSE: Surgical reconstruction is the current standard for ACL rupture treatment in active individuals. Recently, there is renewed interest in primary repair of proximal ACL tears. Despite this, ACL biology and healing potential are currently not well understood. Vascularity is paramount in ACL healing; however, previous ACL vascularity studies have been limited to qualitative histological and dissection-based techniques. The study objective was to use contrast-enhanced quantitative-MRI to compare relative perfusion of proximal, middle, and distal thirds of the in situ ACL. We hypothesized perfusion would be greatest in the proximal third. METHODS: Fourteen cadaveric knees were studied (8 females, 6 males), age 25-61 years. Superficial femoral, anterior tibial, and posterior tibial arteries were cannulated; without intraarticular dissection. Contrast-enhanced quantitative-MRI was performed using a previously established protocol. ACL regions corresponding to proximal, middle, and distal thirds were identified on sagittal-oblique pre-contrast images. Signal enhancement (normalized to tibial plateau cartilage) was quantified to represent regional perfusion as a percentage of total ACL perfusion. Comparative statistics were computed using repeated measures ANOVA, and pairwise comparisons performed using the Bonferroni method. RESULTS: Relative perfusion to proximal, middle, and distal ACL zones were 56.0% ±17.4%, 28.2% ±14.6%, and 15.8% ±16.3%, respectively (p = 0.002). Relative perfusion to the proximal third was significantly greater than middle (p = 0.007) and distal (p = 0.001). No statistically relevant difference in relative perfusion was found to middle and distal thirds (p = 0.281). Post-hoc subgroup analysis demonstrated greater proximal perfusion in males (66.9% ± 17.3%) than females (47.8% ± 13.0%), p = 0.036. CONCLUSION: Using quantitative-MRI, in situ adult ACL demonstrated greatest relative perfusion to the proximal third, nearly 2 times greater than the middle third and 3 times greater than the distal third. Knowledge of differential ACL vascular supply is important for understanding pathogenesis of ACL injury and the process of biological healing following various forms of surgical treatment.

Relative Sagittal Alignment of the Medial and Lateral Articular Surfaces of the Tibial Plateau Using Radiographic Parameters: A Radiographic Cadaveric Study.

OBJECTIVES: To characterize anatomic slope (sagittal alignment) of medial and lateral articular surfaces of the tibial plateau using x-ray and computed tomography (CT). METHODS: Fluoroscopy was used to acquire "perfect" anteroposterior (AP) images of 8 cadaveric knees by tilting a C-arm through a 30-degree cranial/caudal arc in 0.5-degree increments. Five surgeons independently selected perfect AP images that most accurately profiled medial and lateral articular surfaces. Corresponding angles were used to define tangent subchondral structures on sagittal CT that were considered as dominant bony landmarks in a protocol to determine tibial slope on sagittal CT in 46 additional cadaveric knees. RESULTS: Mean perfect C-arm AP angles were 4.2 degrees ± 2.6 degrees posterior for the medial plateau and 5.0 degrees ± 3.8 degrees posterior for the lateral plateau. It was noted that images acquired within a range of angles (medial range, 1.8 degrees ± 0.7 degrees; lateral range, 3.9 degrees ± 3.8 degrees) rather than a single angle adequately profiled each compartment. Using the CT protocol, mean medial slope (5.2 degrees ± 2.3 degrees posterior; range, 0.9-11.5 degrees) was less than lateral slope (7.5 degrees ± 3.0 degrees posterior; range 0.6-12.5 degrees; P < 0.001) in 54 knees. The difference between medial and lateral slopes in any individual specimen ranged from 3.1 degree more medially to 6.8 degrees more laterally. No differences were noted between right and left knees in paired specimens. CONCLUSIONS: On average, tibial slope in the lateral plateau is slightly greater than that in the medial plateau, and variation exists between compartments across patients. Because tibial slope is similar between contralateral limbs, evaluating slope on the uninjured side can provide a template for sagittal plane reduction of tibial plateau fractures.

Surgical outcomes of dual-plate fixation for periprosthetic femur fractures around a stable hip arthroplasty stem.

INTRODUCTION: The incidence of periprosthetic femur fractures is increasing. Multiple treatment methods exist to treat fractures surrounding stable hip arthroplasty implants including locking plate fixation, cable fixation, allograft augmentation, and revision arthroplasty. No consensus regarding optimal treatment has been reached, and significant complications remain. Recently, biomechanical studies have demonstrated the benefits of orthogonal dual-plate fixation, but little clinical data exist. The purpose of the current study was to investigate the clinical and radiographic outcomes of dual-plated periprosthetic femur fractures around stable hip stems. MATERIALS AND METHODS: Patients with periprosthetic femur fractures following hip arthroplasty with a stable femoral stem treated with dual-plate fixation were identified through chart review at a single institution. Fracture classification, fixation characteristics, radiographic outcomes, clinical outcomes and complications including re-operation were recorded. RESULTS: Over a 12-year period, 31 patients (mean age 77 years at surgery, range 48-94) underwent dual plating by three traumatologists for implant-stable periprosthetic femur fractures surrounding a hip arthroplasty stem. There were 27 Vancouver B1-type and 9 inter-prosthetic fractures. Average follow-up was 2 years. Of the 26 patients with minimum 6-month follow-up, 24 (92%) united after index surgery (mean time to union 6.0 months, range 1.5-14.0). Mean time to full weight-bearing post-operatively was 2.6 months (range 1.5-4.0 months). Two patients required secondary surgery to address nonunion. CONCLUSIONS: Dual-plating achieved high union rates with an acceptable complication profile for the treatment of periprosthetic femur fractures surrounding a stable hip arthroplasty stem. Our preferred fixation construct involves a lateral plate spanning the entire femur secured with non-locking bicortical screws supplemented with an anteriorly based reconstruction plate. Additional prospective research is required to confirm the results of this study.

The effect of calcar femoral neck plating on vascularity of the femoral head and neck.

AIMS: Surgical treatment of young femoral neck fractures often requires an open approach to achieve an anatomical reduction. The application of a calcar plate has recently been described to aid in femoral neck fracture reduction and to augment fixation. However, application of a plate may potentially compromise the regional vascularity of the femoral head and neck. The purpose of this study was to investigate the effect of calcar femoral neck plating on the vascularity of the femoral head and neck. METHODS: A Hueter approach and capsulotomy were performed bilaterally in six cadaveric hips. In the experimental group, a one-third tubular plate was secured to the inferomedial femoral neck at 6:00 on the clockface. The contralateral hip served as a control with surgical approach and capsulotomy without fixation. Pre- and post-contrast MRI was then performed to quantify signal intensity in the femoral head and neck. Qualitative assessment of the terminal arterial branches to the femoral head, specifically the inferior retinacular artery (IRA), was also performed. RESULTS: Quantitative MRI revealed a mean reduction of 1.8% (SD 3.1%) of arterial contribution in the femoral head and a mean reduction of 7.1% (SD 10.6%) in the femoral neck in the plating group compared to non-plated controls. Based on femoral head quadrant analysis, the largest mean decrease in arterial contribution was in the inferomedial quadrant (4.0%, SD 6.6%). No significant differences were found between control and experimental hips for any femoral neck or femoral head regions. The inferior retinaculum of Weitbrecht (containing the IRA) was directly visualized in six of 12 specimens. Qualitative MRI assessment confirmed IRA integrity in all specimens. CONCLUSION: Calcar femoral neck plating at the 6:00 position on the clockface resulted in minimal decrease in femoral head and neck vascularity, and therefore it may be considered as an adjunct to laterally-based fixation for reduction and fixation of femoral neck fractures, especially in younger patients. Cite this article: Bone Jt Open 2021;2(8):611-617.

Quantitative assessment of the vascularity of the skeletally immature patella: a cadaveric study using MRI.

PURPOSE: While predominant blood supply to the adult patella enters inferomedially, little is known about skeletally immature patellar perfusion. Improved knowledge of immature patella vascularity can further understanding of osteochondritis dissecans, dorsal defects of the patella and bipartite patella, and help ensure safe surgical approaches. We hypothesized that the immature patella would exhibit more uniform blood flow. The study purpose was to quantify immature patella regional perfusion in comparison with adults. METHODS: Ten cadaveric knees were utilized (five immature, five mature). The superficial femoral artery was cannulated proximally. Signal enhancement increases were compared from pre- to post-contrast MRI to assess relative arterial contributions to patella regions (quadrants, anterior/posterior, superior/inferior, medial/lateral, and outer/inner). RESULTS: Quantitative-MRI analysis revealed similar distribution of enhancement between the immature and mature patella. The inferior pole exhibited significantly higher arterial contribution versus superior pole in both immature and mature groups (p = 0.009; both groups), while the inferomedial quadrant had the highest arterial contribution of all quadrants in both groups. The superolateral quadrant demonstrated the lowest arterial contribution in the immature group and second lowest in the adult group. The patella outer periphery had significantly greater arterial contribution than the inner central region in both immature (p = 0.009) and mature (p = 0.009) groups. CONCLUSION: Distribution of arterial contributions between the immature and mature patella was similar. Our results highlight the importance of inferior and inferomedial blood supply in both immature and mature patellas. These findings have implications for paediatric and adult patients; surgical damage to inferior patellar vessels should be avoided to prevent associated complications.

Increased Vascularity in the Neonatal versus Adult Meniscus: Evaluation with Magnetic Resonance Imaging.

Objective. Quantification of meniscus vascularity has been limited with previous techniques, and minimal data exist describing differential vascular zones in the skeletally immature meniscus. The objective of this study is to use quantitative contrast-enhanced magnetic resonance imaging (MRI) to compare meniscal vascularity in neonatal specimens with adults. We hypothesized that the developing meniscus has greater and more uniform vascularity throughout all zones. Design. Ten fresh-frozen human cadaveric knees (5 neonatal, age 0-6 months; 5 adult, 34-67 years) underwent gadolinium-enhanced MRI using an established vascularity quantification protocol. Regions of interest corresponding to peripheral and central zones of the meniscus were identified on pre-contrast coronal images, and signal enhancement within the same regions (normalized against background tissue) was compared between pre- and post-contrast images. Results. The medial and lateral menisci had similar distribution of perfusion (45.8% ± 8.1% medial vs. 54.2% ± 8.1% lateral in neonatal knees; 50.6% ± 11.3% medial vs. 49.4% ± 11.3% lateral in adult knees, P = 0.47). Increased perfusion was demonstrated in the periphery compared with the central zone (2.3:1 in neonatal knees and 3.25:1 in adult knees, P = 0.31). Neonatal specimens demonstrated 6.0-fold greater overall post-contrast meniscal signal enhancement compared with adults (P < 0.0001), with the 0-month specimen demonstrating the greatest proportional signal enhancement. Conclusions. While blood flow to the periphery is greater than to central zones in all menisci, younger menisci receive proportionally greater overall blood flow compared to adults, including to the central zone, suggesting that the immature meniscus is a more biologically active tissue than its adult counterpart.

The effects of dual plating on the vascularity of the distal femur.

AIMS: Dual plating of distal femoral fractures with medial and lateral implants has been performed to improve construct mechanics and alignment, in cases where isolated lateral plating would be insufficient. This may potentially compromise vascularity, paradoxically impairing healing. This study investigates effects of single versus dual plating on distal femoral vascularity. METHODS: A total of eight cadaveric lower limb pairs were arbitrarily assigned to either 1) isolated lateral plating, or 2) lateral and medial plating of the distal femur, with four specimens per group. Contralateral limbs served as matched controls. Pre- and post-contrast MRI was performed to quantify signal intensity enhancement in the distal femur. Further evaluation of intraosseous vascularity was done with barium sulphate infusion with CT scan imaging. Specimens were then injected with latex medium and dissection was completed to assess extraosseous vasculature. RESULTS: Quantitative MRI revealed a mean reduction of 21.2% (SD 1.3%) of arterial contribution in the lateral plating group and 25.4% (SD 3.2%) in the dual plating group (p = 0.051); representing a mean decrease in arterial contribution of 4.2%. The only significant difference found between both experimental groups was regionally, at the lateral aspect of the distal femur with a mean drop in arterial contribution in the lateral plating group of 18.9% (SD 2.6%) versus 24.0% (SD 3.2%) in the dual plating group (p = 0.048), representing a mean decrease in arterial contribution of 5.1%. Gross dissection revealed complete destruction of periosteal vessels underneath either medial or lateral plates in both groups. The network of genicular branches contributing to the posterior and distal femoral condyles was preserved in all specimens. A medial vascular pedicle was found dividing from the superficial femoral artery at a mean 12.7 cm (SD 1.7) proximal to the medial epicondyle and was undisrupted in the dual plating group. CONCLUSION: Lateral locking-plate application resulted in mean 21.2% reduction in distal femur vascularity. Addition of medial plates did not further markedly decrease vascularity. As such, the majority of the vascular insult occurred with lateral plating alone. Supplemental medially based fixation did not lead to marked devascularization of the distal femur, and should therefore be considered in the setting of comminution and poor bone stock in distal femoral fractures. Further clinical research is required to confirm the results of this study. Cite this article: Bone Joint J 2020;102-B(4):530-538.

Femoral Head Vascularity: Implications Following Trauma and Surgery About the Hip.

Traumatic injury and surgical intervention about the hip joint place the arterial supply to the femoral head (FH) at risk. Compromised perfusion may lead to FH ischemia, cell death, and osteonecrosis. Progression to FH collapse may lead to pain, functional impairment, and decreased quality of life, especially in younger patients. This review describes the arterial supply to the FH, analyzes the impact of femoral neck fractures on FH vascularity, and explores the vascular implications of various surgical interventions about the hip, offering specific techniques to minimize iatrogenic damage to the vessels supplying the FH. [Orthopedics. 2019; 42(5):250-257.].

Periprosthetic femoral nonunions treated with internal fixation and bone grafting.

INTRODUCTION: Periprosthetic femoral nonunions (PPFN) have a reported incidence of 3-9%. Literature on PPFN management is scarce. The study aim was to review combined results of two academic teaching hospitals using comparable PPFN treatment strategies. MATERIALS AND METHODS: A retrospective review was conducted of all patients treated for a PPFN between February 2005 and December 2016. All patients treated with internal fixation for a PPFN with complete clinical and radiological follow-up until healing were included. Nineteen patients were identified (mean age 71.2 years, range 49-87). Treatment consisted of failed hardware removal, debridement, reduction, and rigid internal fixation with or without bone graft. For revision PPFN surgery, use of dual-plating and bone graft augmentation was common. RESULTS: Eighteen of 19 patients (94.7%) progressed to osseous union. One patient was converted to a total femoral prosthesis. No patients were lost to follow-up. All were ambulatory at last follow-up and mean follow-up was 39.8 months. Fourteen patients (73.7%) united after our index nonunion surgery at mean 9.8 months. Five patients (26.3%) required revision surgery after our index nonunion treatment and in 4 of these cases union was achieved at mean 18.0 months. CONCLUSIONS: Our results suggest debridement, revision of fixation and liberal use of bone grafting can lead to reliable healing in the majority of PPFNs. For those PPFNs that do not heal following initial treatment, good healing potential persists with an additional procedure. LEVEL OF EVIDENCE: Prognostic Level III.

Osseous Vascularity of the Medial Elbow After Ulnar Collateral Ligament Reconstruction: A Comparison of the Docking and Modified Jobe Techniques.

BACKGROUND: Although vascularity plays a critical role in healing after ulnar collateral ligament (UCL) reconstruction, intraosseous blood flow to the medial epicondyle (ME) and sublime tubercle remains undefined. PURPOSE: To quantify vascular disruption caused by tunnel drilling with the modified Jobe and docking techniques for UCL reconstruction. STUDY DESIGN: Controlled laboratory study. METHODS: Eight matched pairs (16 specimens) of fresh-frozen cadaveric upper extremities were randomized to 1 of 2 study groups: docking technique or modified Jobe technique. One elbow in each pair underwent tunnel drilling by the assigned technique, while the contralateral elbow served as a control. Pregadolinium and postgadolinium magnetic resonance imaging were performed to quantify intraosseous vascularity within the ME, trochlea, and proximal ulna. Three-dimensional computed tomography (CT) and gross dissection were performed to assess terminal vessel integrity. RESULTS: Ulnar tunnel drilling had minimal impact on vascularity of the proximal ulna, with maintenance of >95% blood flow for each technique. Perfusion in the ME was reduced 14% (to 86% of baseline) for the docking technique and 60% (to 40% of baseline) for the modified Jobe technique (mean difference, 46%; P = .029). Three-dimensional CT and gross dissection revealed increased disruption of small perforating vessels of the posterior aspect of the ME for the modified Jobe technique. CONCLUSION: Although tunnel drilling in the sublime tubercle appears to have a minimal effect on intraosseous vascularity of the proximal ulna, both the docking and modified Jobe techniques reduce flow in the ME. This reduction was 4 times greater for the modified Jobe technique, and these findings have important implications for UCL reconstruction surgery. CLINICAL RELEVANCE: As the rate of revision UCL reconstructions continues to rise, investigation into causes for failure of primary surgery is needed. One potential cause is poor tendon-to-bone healing due to inadequate vascularity. This study quantifies the amount of vascular insult that is incurred in the ME during UCL reconstruction. While vascular insult is only one of many factors that affects the surgical success rate, surgeons performing this procedure should be mindful of this potential for vascular disruption.

Quantitative and Qualitative Assessment of the Relative Arterial Contributions to the Calcaneus.

BACKGROUND: The purpose of this study was to quantitatively and qualitatively assess relative arterial contributions to the calcaneus. METHOD: Fourteen cadaveric ankle pairs were used. In each specimen, the posterior tibial artery, peroneal artery, and anterior tibial artery were cannulated and used for contrast-enhanced magnetic resonance imaging (MRI) and computed tomography (CT). Quantitative MRI analysis of the pre- and postcontrast MRI scans facilitated assessment of relative arterial contributions. In addition, postcontrast MRIs were used to measure all perfused arterial entry points and scaled to a 3-dimensional calcaneus model. Contrast-enhanced CT imaging was assessed to further delineate the extraosseous arterial course. Two pairs underwent infusion of diluted BaSO4 through a constant-pressure pump using extended infusion duration. RESULTS: Quantitative MRI findings indicated the peroneal artery provided 52.6% of the calcaneal arterial supply, 31.6% from the posterior tibial artery, and 15.8% from the anterior tibial artery. The cortical entry points were found in fairly consistent patterns along calcaneal cortical surfaces. All specimens demonstrated intraosseous anastomoses between lateral and medial entry points at common locations. CONCLUSIONS: The peroneal artery was found to provide the largest calcaneal arterial contribution, followed by the posterior tibial artery and anterior tibial artery. A rich anastomotic arterial network was found supplying the calcaneus. CLINICAL RELEVANCE: This study provides quantitative and qualitative findings of the relative arterial contribution of the calcaneus. This knowledge can help expand our understanding of calcaneal vascularization, demonstrate the vascular impact of calcaneal fracture and surgery, and facilitate future research on the arterial anatomy of the calcaneal soft tissue envelope.

Quantitative Assessment of Femoral Head Perfusion Following Arthroscopic Femoral Osteochondroplasty: A Cadaveric Study.

BACKGROUND: Disruption of the arterial supply to the femoral head, and subsequent development of femoral head osteonecrosis, is of serious concern with intracapsular hip procedures. However, the effect of arthroscopic femoral osteochondroplasty on femoral head perfusion is unknown. We aimed to quantify the effects of both standard and posterosuperior extension of arthroscopic femoral osteochondroplasty on femoral head vascularity. We hypothesized that extension of the superior resection zone posteriorly would negatively affect femoral head perfusion. METHODS: In 12 cadaveric pelvic specimens, we cannulated the medial femoral circumflex artery (MFCA). One hip per pelvis was randomly selected to be in 1 of 2 experimental groups based on the superior extent of the osteochondroplasty: standard resection (resection anterior to the 12 o'clock [0° of 360°] position) or extended resection (resection extended posterior to the 12 o'clock position). Computed tomography (CT) scans were obtained prior to and following arthroscopic resection to delineate the resection margins. Gadolinium enhancement on magnetic resonance imaging (MRI) was quantified in the femoral head by volumetric analysis using custom software. A polyurethane compound was injected and gross dissection of the vasculature was performed. RESULTS: Extension of the osteochondroplasty posteriorly (the extended-resection group), to a mean of 41.3° (range, 34° to 47°) posterior to the 12 o'clock position, decreased femoral head perfusion by a mean of 28% (range, 18% to 38%). The standard-resection group demonstrated a mean decrease in femoral head perfusion of 7% (range, 4% to 11%). Correlation analysis demonstrated a significant negative correlation (correlation coefficient, -0.877; p < 0.001; R = 0.747). For every 1° that the superior resection margin extended posteriorly, a corresponding 0.88% decrease in femoral head perfusion was found. CONCLUSIONS: Femoral head perfusion is almost fully maintained with arthroscopic osteochondroplasty when the superior resection margin is anterior to the 12 o'clock position. Perfusion is also well maintained if the superior resection margin is extended no more than 10° posterior to 12 o'clock. Further posterior extension correlated with greater decreases in femoral head perfusion. CLINICAL RELEVANCE: Our study provides previously unreported quantitative MRI data on femoral head perfusion following arthroscopic femoral osteochondroplasty for the treatment of cam-type femoroacetabular impingement.

Anterolateral Approach to the Pilon.

This video reviews the indications, surgical approach, and case examples of the anterolateral approach to a distal tibial plafond fracture. If this approach is used in a staged fashion, when the soft envelope is ready, it affords excellent visualization for fracture fixation through thick skin flaps. An associated article reviews a cohort of 44 mainly type C3 pilon injuries treated by 2 orthopaedic traumatologist using the anterolateral approach after staged external fixation. An anatomic or good fracture reduction was obtained in 41 fractures with 13.6% of patients undergoing a secondary surgical procedure for infection or nonunion.

A Vessel-Preserving Surgical Hip Dislocation Through a Modified Posterior Approach: Assessment of Femoral Head Vascularity Using Gadolinium-Enhanced MRI.

BACKGROUND: Surgical hip dislocation allows circumferential access to the femoral head and acetabulum and is utilized in the treatment of intra-articular hip disorders. Surgical hip dislocation is currently performed with a trochanteric osteotomy that reliably preserves the femoral head arterial supply; however, trochanteric nonunion or painful hardware requiring removal may occur. In a cadaveric model, using gadolinium-enhanced magnetic resonance imaging (MRI) and gross dissection, we evaluated whether modifications to the posterior approach preserve the femoral head arterial supply after a posterior surgical hip dislocation. METHODS: In eight fresh-frozen pelvic specimens, a surgical hip dislocation was performed through the posterolateral approach with modifications in the tenotomy of the short external rotators and a capsulotomy designed to preserve the medial femoral circumflex artery (MFCA). Modifications included tenotomies of the quadratus femoris, conjoined tendon of the short external rotators, and obturator externus made 2.5 cm medial to their insertion on the greater trochanter and a T-type capsulotomy originating below the cut edge of the obturator externus tendon and continuing circumferentially along the acetabular rim. After hip dislocation, the MFCA was cannulated and MRI scans were acquired before and after gadolinium enhancement for evaluation of femoral head perfusion, with the contralateral hip, which was left intact, used as a control. Anatomic gross dissection was performed after the injection of polyurethane in the MFCA and confirmed MFCA vessel integrity. RESULTS: Quantitative MRI showed that the operatively treated hip retained a mean perfusion (and standard deviation) of 95.6% ± 9.7% in the femoral head and 94.7% ± 21.5% in the femoral head-neck junction compared with the control hip (p = 0.66 and p = 0.85, respectively). Dissection after polyurethane injection confirmed that the superior retinacular and inferior retinacular arteries entering the femoral head were intact in all specimens. CONCLUSIONS: In a cadaveric model using gadolinium-enhanced MRI, we found that standardized modifications to the posterior approach, specifically with regard to the location of the short external rotator tenotomy and capsulotomy, successfully preserved the femoral head arterial supply after posterior surgical hip dislocation. CLINICAL RELEVANCE: While further research is necessary before these modifications can be recommended for widespread clinical use, the results of this study suggest the extracapsular vascular anatomy can be safely preserved during posterior surgical hip dislocation.