Treatment of Recurrent Dislocation after Total Hip Arthroplasty Using Advanced Imaging and Three-Dimensional Modeling Techniques: A Case Series.

BACKGROUND: Surgical treatment options for addressing recurrent dislocation after total hip arthroplasty (THA) vary. Identifying impingement mechanisms in an unstable THA may be beneficial in determining appropriate treatment. QUESTIONS/PURPOSES: We sought to assess the effectiveness of developing pre-operative plans for treating hip instability after THA. We used advanced imaging and three-dimensional modeling techniques to perform impingement analyses in patients with unstable THA. METHODS: We evaluated a series of eight patients who would require revision THA to treat recurrent dislocation. Using a pre-operative algorithmic approach, we built patient-specific models and evaluated hip range of motion with computed tomographic scanning and biplanar radiography. This information was used to determine a surgical treatment plan that was then executed intra-operatively. Patients were followed for 2 years to determine whether they experienced another hip dislocation following treatment. RESULTS: Pre-operative kinematic modeling showed four of the eight patients had limited hip range of motion during flexion and internal rotation; a prominent anterior inferior iliac spine (AIIS) was found to limit hip range of motion in some of these cases. In the other four patients, range of motion was acceptable, suggesting soft-tissue causes of dislocation. No patients in this series experienced dislocation after undergoing revision THA. CONCLUSION: Advanced modeling techniques may be useful for identifying the impingement mechanisms responsible for instability after THA. Once variables contributing to limited hip range of motion are identified, surgeons can develop treatment plans to improve patient outcomes. Resecting a hypertrophic AIIS may improve hip range of motion and may be an important consideration for hip surgeons when revising unstable THAs.

Biomechanical Assessment of a Novel Posterior Soft Tissue Repair Technique in Primary Total Hip Arthroplasty.

INTRODUCTION: Instability is one of the most common complications after total hip arthroplasty (THA), particularly when using the posterior approach. Repair of the posterior capsule has proven to significantly decrease the incidence of posterior hip dislocation. The purpose of the present study is to evaluate if a racking hitch knot utilizing a 2mm braided polyblend suture provides a stronger repair of the posterior soft tissues when compared to a traditional repair utilizing a non-absorbable suture after a posterior approach to the hip. MATERIALS AND METHODS: Ten cadaveric hips from donors, who were at a mean age of 80 ± 9 years old at the time of death, were evaluated after posterior soft tissue repair utilizing two different techniques. Five specimens were repaired utilizing a racking hitch knot with a 2mm braided polyblend suture (FiberTape®, Arthrex GmbH, Naples, Florida) and five other specimens were repaired with a traditional repair using a no. 2 non-absorable suture (FiberWire®, Arthrex GmbH, Naples, Florida). Cadaveric specimens were matched based upon age, sex, and laterality. Biomechanical tensile testing using the Instron E10000 Mechanical Testing System and the mechanisms of failure (MOF) were assessed. RESULTS: The ultimate load to failure was three times higher using braided polyblend sutures (390.00 ± 129.08 N) compared to non-absorbable sutures (122.81 ± 82.41 N) after posterior soft tissue repair (p<0.01). In the braided polyblend suture cohort, the mechanism of failure most commonly occurred as the braided suture pulled through the posterior soft tissues. However, in the non-absorbable suture repair, failure took place at the suture knot. CONCLUSION: The use of our posterior capsular repair utilizing a braided polyblend suture and racking hitch knot provides for a stronger repair of the posterior soft tissues when compared to non-absorbable suture repair following a posterior approach to the hip joint.

Percutaneous treatment of ranulas: ultrasound-guided drainage with salivary gland chemical ablation.

BACKGROUND: Ranulas are salivary pseudocysts in the floor of the mouth adjacent to damaged salivary glands. Current surgical management is drainage of the ranula with removal of the offending gland. An analogous percutaneous procedure could potentially offer similar treatment efficacy in a more minimally invasive way. OBJECTIVE: To evaluate the outcomes of a cohort of patients with ranulas treated with percutaneous ranula aspiration and chemical ablation of the source salivary gland to see whether this technique could be proposed as a minimally invasive treatment alternative. MATERIALS AND METHODS: This retrospective single-center study evaluated 24 patients treated percutaneously for ranulas between January 2004 and December 2014. All patients were treated with percutaneous ranula aspiration and chemical ablation of the offending salivary gland. Treatment success and any complications were recorded. RESULTS: Complete ranula eradication was successfully accomplished in 87.5% of the patients with no complications. CONCLUSION: Initial results suggest that our technique of percutaneous aspiration of ranulas and chemical ablation of the source salivary gland is safe and effective.

Radiographic and Clinical Outcomes Following Robotic-Assisted Lateral Unicompartmental Knee Arthroplasty.

Much advancement has been made in the treatment of knee arthritis. A special area of interest has been the treatment of medial unicompartmental disease. However, patients with isolated lateral compartment arthritis represent a significant subset of the population. Lateral unicompartmental knee arthroplasty (UKA) is performed much less frequently than in the medial compartment and is known to be more technically demanding and less reproducible. Robotic-assisted arthroplasty provides a tool to improve component placement and reproducibility. The purpose of this study is to retrospectively review radiographic and clinical outcomes following robotic-assisted lateral UKA. We retrospectively reviewed 22 patients who underwent robotic-assisted lateral UKA by a single surgeon. Indications consisted of isolated lateral compartment arthritis with correctable valgus deformity and an intact anterior cruciate ligament. Eighteen patients met all inclusion criteria, resulting in 20 lateral UKA. Radiographic and clinical outcomes were evaluated and we found that robotic assistance during lateral UKA provided accurate and reproducible results. Native alignment of the tibia and femur were well maintained in the coronal and sagittal planes, and no overcorrection occurred. The standard deviation of tibial components was 1.8°, indicating strong accuracy and reproducibility. Operative times were increased, but this did not lead to intraoperative complications or slowed progression of postoperative rehabilitation. Robotic-assisted lateral UKA provides a tool for accurate and reproducible component placement with excellent short-term clinical outcomes.

Difficulty of Total Hip Arthroplasty Following Open Reduction and Internal Fixation of Acetabular Fractures.

BACKGROUND: The incidence of posttraumatic arthrosis after acetabular fractures is significant, and patients frequently require secondary total hip arthroplasty. Conversion arthroplasty is more technically difficult, and there is higher risk than with routine primary total hip arthroplasty. The goal of this study was to identify the challenges and risks of secondary total hip arthroplasty compared to primary total hip arthroplasty. METHODS: We retrospectively identified 30 patients who underwent secondary total hip arthroplasty after open reduction and internal fixation of an acetabulum fracture and compared them with 20 patients who had undergone primary total hip arthroplasty for degenerative joint disease. RESULTS: Demographic data were similar between groups. Hardware removal was deemed necessary in 21 patients (70%). Allograft was needed for bone defects in 33% of secondary total hip arthroplasty cases, while no primary cases required grafting. Operative time (217.4 vs. 113.7 min, P < 0.01) and estimated blood loss (875.8 vs. 365 mL, P < 0.01) were significantly greater in the secondary arthroplasty group. Early postoperative complications were also higher in the secondary arthroplasty group. CONCLUSIONS: Total hip arthroplasty after acetabular fracture open reduction and internal fixation is a more complex procedure due to exposure difficulty, possible implant removal, management of bony deficits, and the potential use of cages and revision components. Experienced surgeons managing these complicated cases must take great care not only in ensuring appropriate technique but also in appropriate patient education regarding increased risk of major and minor complications. LEVEL OF EVIDENCE: Level III.

Direct Anterior Approach Has Lower Deep Infection Frequency Than Less Invasive Direct Lateral Approach in Primary Total Hip Arthroplasty.

Debate continues over the direct anterior (DA) approach. The purpose of this study is to compare the frequency of deep infection between a DA approach and a less invasive direct lateral (LIDL) approach in a large consecutive series of primary total hip arthroplasty (THA). The authors identified 5702 primary THAs performed between 2007 and 2014. DA approach was used in 3540 hips and LIDL in 2162. Patient records were reviewed. Statistical analysis of reoperation, infection- or wound-related complication, and deep infection was performed. During the 8-year follow-up period, there were 98 reoperations in the DA group (2.8%) and 77 in the LIDL group (3.6%; p = .09 NS). Wound- or infection-related reoperation occurred in 32 DA THAs (0.9%) versus 36 LIDL THAs (1.7%; p = .01). Deep infection occurred in 7 DA THAs (0.2%) versus 21 LIDL THAs (0.97%; p > .0001). The risk of deep infection was statistically lower in the DA approach. (Journal of Surgical Orthopaedic Advances 27(1):21-24, 2018).

Ankle Arthrodesis: A Retrospective Analysis Comparing Single Column, Locked Anterior Plating to Crossed Lag Screw Technique.

Ankle arthrodesis is performed to eliminate pain due to end-stage osteoarthritis, regardless of etiology. This procedure remains the reference standard treatment for end-stage ankle arthritis, despite recent advancements in total ankle replacement. The objective of the present study was to retrospectively evaluate the radiographic and clinical fusion rates and time to bony fusion for patients who underwent ankle arthrodesis using an anterior approach with a single column locked plate construct versus crossed lag screws. We identified 358 patients who had undergone ankle arthrodesis from January 2003 to June 2013. Of the 358 patients, 83 (23.2%) met the inclusion criteria for the present study. Of the 83 included patients, 47 received locked anterior (or anterolateral) plate fixation, and 36 received crossed lag screw constructs. The overall nonunion rate was 6.0% (n = 5), with 1 nonunion in the anterior plate group (2.1%) and 4 nonunions in the crossed lag screw group (11.1%; p = .217). No differences were identified between the 2 groups for normal talocrural angle [χ2 (1) = 0.527; p = .468], normal tibial axis/talar ratio [χ2 (1) = 0.004; p = .952], and lateral dorsiflexion angle (p = .565). Based on our findings in similar demographic groups, ankle arthrodesis using locked anterior plate fixation is a safe technique with similar complication rates and radiographic outcomes to those of crossed lag screws.

Pediatric Diaphyseal Femur Fractures: Submuscular Plating Compared With Intramedullary Nailing.

This study compared the radiographic and clinical outcomes of pediatric diaphyseal femur fractures treated by submuscular plating, flexible retrograde intramedullary nailing, or rigid antegrade intramedullary nailing with a trochanteric entry point in skeletally immature patients who were 8 years and older. A retrospective review was conducted of skeletally immature patients 8 years and older who were treated for femur fracture with submuscular plating, flexible intramedullary nailing, or rigid intramedullary nailing from 2001 to 2014 with a minimum 12-week follow-up. Treatment outcomes were compared for statistical significance, including time to union, malunion, nonunion, heterotopic ossification, avascular necrosis, time to full weight bearing, limb length discrepancy, residual limp, painful hardware, and infection. The study identified 198 femur fractures in 196 patients (mean age, 11.9 years). Each femur fracture was treated with submuscular plating (35), flexible intramedullary nailing (61), or rigid intramedullary nailing (102). Mean follow-up across the cohort was 48 weeks, ranging from 12 to 225 weeks. Flexible nailing was associated with an increased incidence of malunion (P<.0001) and hardware irritation (P=.0204) and longer time to full weight bearing (P=.0018). Rigid nailing was associated with an increased incidence of limp at 12-week followup (P=.0412). Additionally, 23.5% of patients who were treated with rigid nailing had heterotopic ossification. Of all surgical methods, submuscular plating allowed for the most rapid return to full weight bearing (mean, 7 weeks) and offered the fastest healing rate (mean, 6 weeks). Submuscular plating resulted in faster times to union and full weight bearing, with minimal complication rates. Rigid intramedullary nailing with trochanteric entry resulted in a lower incidence of malunion and hardware-related complications; however, these patients had an increased incidence of heterotopic ossification and residual limp postoperatively. Flexible retrograde intramedullary nailing resulted in the highest rates of malunion and hardware irritation and the longest time to full weight bearing. [Orthopedics. 2016; 39(6):353-358.].

Bridge Plating Length-Unstable Pediatric Femoral Shaft Fractures.

The treatment of pediatric diaphyseal femur fractures, particularly length-unstable fractures, continues to be an area of controversy in patients from age 6 to skeletal maturity. Submuscular bridge plating is an alternative that allows for stable internal fixation while minimizing soft tissue disruption. We describe a surgical technique that has simplified both implantation and removal. This technique provides a stable construct in comminuted and unstable fracture patterns allowing for early mobilization with minimal complications.

Treatment of the Failed Modular Neck Stems: Tips and Tricks.

BACKGROUND: Modular femoral components emerged because of the advantages of recreating limb length, offset, and native femoral version in total hip arthroplasty. Despite its potential benefits, the increase in modularity at the head-neck junction can lead to corrosion and subsequently failure of the implant. METHODS: We present 3 case examples of patients who underwent revision surgery secondary to corrosion of their modular femoral components. RESULTS: Issues addressed include understanding corrosion at the head-neck junction, presentations of adverse local tissue reactions, efficacy of metal ion testing and metal artifact reduction sequence magnetic resonance imaging, and approaches to revision surgery for failed modular neck stems. CONCLUSIONS: When revision surgery is indicated for failed modular neck stems, we recommend a thoughtful approach with contemporary extraction techniques and options to enhance stability. Furthermore, long-term follow-up is needed to define the growing effect of modularity in total hip arthroplasty.

Prevalence of Pseudotumor in Patients After Metal-On-Metal Hip Arthroplasty Evaluated with Metal Ion Analysis and MARS-MRI.

The purpose of this study is to quantify the prevalence of pseudotumors in patients with well-functioning and painful metal-on-metal total hip arthroplasty, to characterize the pseudotumor with the use of MARS-MRI, and to assess the relationship between pseudotumors and metal ions. We retrospectively reviewed 102 single surgeon patients. The results showed that 68.6% developed pseudotumor with 60.9% of the asymptomatic group developing pseudotumor. The symptomatic group had a higher proportion of patients with elevated serum cobalt levels (P=0.035). There was no difference found with elevated metal ions and prevalence of pseudotumor, but elevated cobalt levels were associated with larger pseudotumor size (P=0.001). The available evidence indicated that most patients that develop pseudotumors are asymptomatic, and that elevated serum cobalt levels may be associated with symptoms and pseudotumor size.

Radiofrequency ablation of a cervical osteoid osteoma: a trans-thyroid approach.

We present a 16-year-old girl with an osteoid osteoma in the vertebral body of C5. Given the difficulty of surgically treating the lesion, radiofrequency ablation was used. Percutaneous needle access to this lesion in the anterior aspect of the cervical vertebral body was limited by the many critical adjacent structures. We present our successful treatment of this lesion utilizing a trans-thyroid needle approach.