Craig E. Klinger

Sciatic Nerve Release Following Fracture or Reconstructive Surgery of the Acetabulum

BACKGROUND Sciatic neuropathy associated with acetabular fractures can result in disabling long-term symptoms. The purpose of this retrospective study was to evaluate the effect of sciatic nerve release on sciatic neuropathy associated with acetabular fractures and reconstructive acetabular surgery. METHODS Between 2000 and 2004, ten patients with sciatic neuropathy associated with an acetabular fracture were treated with release of the sciatic nerve from scar tissue and heterotopic bone. Additional surgical procedures included open reduction and internal fixation of the acetabulum (five patients), removal of hardware and total hip arthroplasty (three patients), and removal of hardware alone (one patient). The average age of the patients was forty-three years. All patients were followed with serial examinations and assessments for a minimum of one year (average, twenty-six months). RESULTS All patients had partial to complete relief of radicular pain, of diminished sensation, and of paresthesias after the nerve release. Four of seven patients with motor loss and two of five patients with a footdrop demonstrated improvement in function after the nerve release. No patient had evidence of worsening on neurologic examination after the release. CONCLUSIONS Sciatic nerve release during reconstructive acetabular surgery can decrease the sensory symptoms of preoperative sciatic neuropathy associated with a previous acetabular fracture. Motor symptoms, however, are less likely to resolve following nerve release.BACKGROUND Sciatic neuropathy associated with acetabular fractures can result in disabling long-term symptoms. The purpose of this retrospective study was to evaluate the effect of sciatic nerve release on sciatic neuropathy associated with acetabular fractures and reconstructive acetabular surgery. METHODS Between 2000 and 2004, ten patients with sciatic neuropathy associated with an acetabular fracture were treated with release of the sciatic nerve from scar tissue and heterotopic bone. Additional surgical procedures included open reduction and internal fixation of the acetabulum (five patients), removal of hardware and total hip arthroplasty (three patients), and removal of hardware alone (one patient). The average age of the patients was forty-three years. All patients were followed with serial examinations and assessments for a minimum of one year (average, twenty-six months). RESULTS All patients had partial to complete relief of radicular pain, of diminished sensation, and of paresthesias after the nerve release. Four of seven patients with motor loss and two of five patients with a footdrop demonstrated improvement in function after the nerve release. No patient had evidence of worsening on neurologic examination after the release. CONCLUSIONS Sciatic nerve release during reconstructive acetabular surgery can decrease the sensory symptoms of preoperative sciatic neuropathy associated with a previous acetabular fracture. Motor symptoms, however, are less likely to resolve following nerve release.

Quantitative and qualitative assessment of bone perfusion and arterial contributions in a patellar fracture model using gadolinium-enhanced magnetic resonance imaging: a cadaveric study.

BACKGROUND The purpose of the present study was to evaluate the anatomy and contribution of the patellar vascular supply and to quantify the effect of a transverse fracture on patellar perfusion. METHODS In twenty matched pairs of fresh-frozen cadaveric knees, the superficial femoral artery, anterior tibialis artery, and posterior tibialis artery were cannulated. One side of each matched pair was randomly selected to undergo one of two osteotomies: (1) midpatellar osteotomy or (2) distal-pole osteotomy. For volumetric analysis, comparisons were performed between contrast-enhanced magnetic resonance images and precontrast magnetic resonance images as well as between osteotomized patellar bone fragments and the corresponding intact areas on the control side. We then injected a urethane polymer compound and dissected all specimens to examine extraosseous vascularity. RESULTS Magnetic resonance imaging demonstrated that the largest arterial contribution to the patella entered at the inferior pole in 100% of the specimens; in 80% of these specimens, the artery entered inferomedially. It also revealed an overall decrease in contrast enhancement in both transverse osteotomy groups, with an average reduction in enhancement in the proximal fragment of 36%. CONCLUSIONS If possible, surgical interventions about the knee should be carefully planned to preserve the peripatellar ring (the source of the entire patellar blood supply), especially the inferior patellar network. Distal-pole patellectomy should be avoided to retain vascularized bone at the reduced fracture site.

Assessment of femoral head and head-neck junction perfusion following surgical hip dislocation using gadolinium-enhanced magnetic resonance imaging: a cadaveric study.

BACKGROUND The purpose of the present study was to quantify perfusion to the femoral head and head-neck junction using gadolinium-enhanced magnetic resonance imaging following three surgical dislocations of the hip (trochanteric flip osteotomy, standard posterior approach, and modified posterior approach). METHODS The medial femoral circumflex artery was cannulated in fifty fresh-frozen cadaveric hips (twenty-five pelvic specimens). One hip on each pelvic specimen was randomly chosen to undergo one of the three surgical dislocations, and the contralateral hip was used as a control. Gadolinium enhancement on the magnetic resonance imaging scan was quantified in both the femoral head and head-neck junction by volumetric analysis using custom magnetic resonance imaging analysis software. A polyurethane compound was then injected, and gross dissection was performed to assess the extraosseous vasculature. RESULTS Magnetic resonance imaging quantification revealed that the trochanteric flip osteotomy group maintained almost full perfusion (mean, 96% for the femoral head and 98% for the head-neck junction). The standard posterior approach almost completely compromised perfusion (mean, 4% for the femoral head and 8% for the head-neck junction). Six specimens in the modified posterior approach group demonstrated partial perfusion (mean, 32% in the femoral head and 26% in the head-neck junction). Three specimens in the modified posterior approach group demonstrated almost full perfusion (mean, 96% in the femoral head and 97% in the head-neck junction). Gross dissection revealed that all specimens in the standard posterior approach group and seven of ten in the modified posterior approach group sustained disruption of the ascending branch of the medial femoral circumflex artery. All specimens in the standard posterior approach group demonstrated disruption of the inferior retinacular artery. The inferior retinacular artery remained intact in nine of ten specimens in the modified posterior approach group. One specimen in the modified posterior approach group that had disruption of both the ascending medial femoral circumflex artery and inferior retinacular artery demonstrated a substantial decrease in perfusion (7% in the femoral head and 5% in the head-neck junction). CONCLUSIONS The trochanteric flip osteotomy preserves the vascular supply to the femoral head and head-neck junction. The standard posterior approach disrupts the vascular supply and should be completely abandoned for surgical hip dislocation. Despite reduced enhancement, substantial perfusion of the femoral head and head-neck junction was present in the modified posterior approach group, likely because of the preservation of the inferior retinacular artery. The modified posterior approach produced variable results, indicating that improvement to the modified posterior approach is needed. CLINICAL RELEVANCE Our study provides previously unreported quantitative magnetic resonance imaging data on the perfusion to the femoral head and head-neck junction during common surgical approaches to the hip.

The effect of entry point on malalignment and iatrogenic fracture with the Synthes lateral entry femoral nail.

Purpose: Multiplanar rigid femoral nails introduced through a lateral entry portal have been associated with a higher risk of iatrogenic fracture and malreduction. This study was designed to investigate if the entry point of the lateral entry femoral nail (Synthes, Paoli, PA) has an impact on alignment of the femur and the incidence of iatrogenic fracture. Materials and Methods: The preoperative and postoperative radiographs of 227 femoral shaft fractures stabilized with the lateral entry femoral nail from 11 different trauma centers were retrospectively evaluated. Reviewers were blinded with respect to outcome and determined whether the starting point for the nail was anterior, middle, or posterior by dividing the greater trochanter into thirds. The corresponding alignment in both the sagittal and coronal planes was determined independently. The occurrence of iatrogenic fractures was documented as well. Results: Of the 227 radiographs reviewed, 167 had acceptable lateral radiographs of the proximal femur to determine the exact location of the entry point. There was high interobserver reliability (κ = 0.87) with regard to the scoring of starting point for the nail. The results for the concordant pairs (n = 154) were as follows: middle third 47%, anterior third 44%, and posterior third 10%. The risk of valgus malalignment is nearly threefold (10% versus 25%) when the starting point is anterior as compared with the middle entry point (risk ratio, 2.6; 95% confidence interval, 1.2-5.9; P = 0.021). There was no association between entry site and varus or apex-anteroposterior angulation. There were a total of 16 iatrogenic fractures in the cohort. Ten of these had adequate lateral hip radiographs, and of these, nine occurred after an anterior entry site. There is strong evidence that an anterior insertion site leads to iatrogenic fracture as compared with a middle entry portal (13% versus 0%, P = 0.001). Conclusions: Accurate entry site within the greater trochanter is essential to prevent malalignment and iatrogenic fractures when using the lateral entry femoral nail to stabilize fractures of the femoral diaphysis. The helical shape of the nail can result in valgus malalignment and fracture if the entry point is too anterior, and surgeons must recognize these consequences of insertion inaccuracy. Meticulous biplanar imaging and experience with this particular implant are important for its precise and safe insertion.

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.

The relative contribution of the medial and lateral femoral circumflex arteries to the vascularity of the head and neck of the femur: a quantitative MRI-based assessment

AIMS We aimed to quantify the relative contributions of the medial femoral circumflex artery (MFCA) and lateral femoral circumflex artery (LFCA) to the arterial supply of the head and neck of the femur. MATERIALS AND METHODS We acquired ten cadaveric pelvises. In each of these, one hip was randomly assigned as experimental and the other as a matched control. The MFCA and LFCA were cannulated bilaterally. The hips were designated LFCA-experimental or MFCA-experimental and underwent quantitative MRI using a 2 mm slice thickness before and after injection of MRI-contrast diluted 3:1 with saline (15 ml Gd-DTPA) into either the LFCA or MFCA. The contralateral control hips had 15 ml of contrast solution injected into the root of each artery. Next, the MFCA and LFCA were injected with a mixture of polyurethane and barium sulfate (33%) and their extra-and intra-arterial course identified by CT imaging and dissection. RESULTS The MFCA made a greater contribution than the LFCA to the vascularity of the femoral head (MFCA 82%, LFCA 18%) and neck (MFCA 67%, LFCA 33%). However, the LFCA supplied 48% of the anteroinferior femoral neck overall. CONCLUSION This study clearly shows that the MFCA is the major arterial supply to the femoral head and neck. Despite this, the LFCA supplies almost half the anteroinferior aspect of the femoral neck. Cite this article: Bone Joint J 2016;98-B:1582-8.

Anterolateral Approach to the Pilon.

Summary: 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.

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.

The Use of Fibular Allograft in Complex Periarticular Fractures Around the Knee

Although the use of fibular strut allografts in proximal humerus fractures has gained popularity, their use in other types of fractures is less well described. Fibular allografts have recently been used in the repair of complex periarticular fractures of the proximal tibia and distal femur. Fibular allografts can be inserted in a variety of manners to achieve goals specific to each individual fracture pattern. In the proximal tibia, insertion through a fracture line or cortical window facilitates joint surface elevation, prevents subsidence and enhances overall construct stability. In distal femoral fractures, including complex periarticular fractures, insertion through the fracture or cortical window permits indirect reduction of the medial cortex and provides necessary medial column support. An additional option in distal femur fractures includes fibula insertion as an intramedullary nail, allowing enhanced fixation in short distal fracture segments. In all cases, the use of a fibular allograft augments poor bone stock and provides improved screw purchase and construct stability when combined with conventional plating methods. Here we present a series of cases at our institution illustrating an array of novel techniques utilizing endosteal fibular allografts in the fixation of complex periarticular fractures about the knee.

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.