How Reliable Is the Absolute Synovial Polymorphonuclear Neutrophil Cell Count in Diagnosing Periprosthetic Joint Infection?

BACKGROUND: Diagnosing periprosthetic joint infection (PJI) is a daunting task for even the most experienced orthopedic surgeons, as there is currently no test available that can provide absolute accuracy. Utilizing an established synovial indicator for detecting PJI without incurring additional costs or resources would be the optimal solution for predicting the presence of infection. Therefore, we hypothesized that synovial absolute neutrophil count (ANC) would improve the diagnostic accuracy of chronic knee and hip PJI. METHODS: The study included 260 patients (134 men and 126 women, mean age of 70 years [range, 26 to 89]) who underwent aspiration during preoperative workup. Of these, 109 patients (41.9%) were diagnosed with chronic PJI (50 knees, 59 hips), and 151 patients (58.1%) were diagnosed as aseptic (94 knees, 57 hips). Data obtained from all patients included age, sex, procedure type (total hip or total knee arthroplasty), operation side, synovial white blood cell count (cells/µL), synovial polymorphonuclear cells percentage, and synovial α-defensin immunoassay value at the admission were retrieved from the electronic medical record. RESULTS: The calculated optimal threshold for synovial ANC of 1,415.5 cells/µL was associated with an area under the receiver operating characteristic curve (AUC) of 0.930 for chronic knee PJI diagnosis. The calculated optimal threshold for synovial ANC of 2,247 cells/µL was associated with an AUC of 0.905 for chronic hip PJI diagnosis. CONCLUSIONS: This study has conclusively shown that the synovial ANC serves as a valuable marker in the complicated diagnosis of PJI. This highly effective and efficient approach should be utilized for obtaining further information through standard tests, thereby ruling out the possibility of PJI. LEVEL OF EVIDENCE: III.

Intramedullary Positive Tissue Culture Increases the Risk of Reinfection Following One-Stage Septic Revision Total Knee Arthroplasty.

BACKGROUND: Intraoperative acquisition of representative tissue samples is essential during revision arthroplasty of the infected total knee arthroplasty (TKA). While the number of intraoperative tissue samples needed to identify the organism is well described in the literature, there is still a paucity of evidence regarding the location of positive intraoperative samples and their correlation to postoperative outcomes. METHODS: There were forty-two patients who had septic failure following one-stage revision TKA for periprosthetic joint infection who were identified between January 2009 and December 2017. They were matched to a control group of patients who had successful one-stage revision TKA without septic failure. The location of positive intraoperative tissue samples was categorized as: 1) soft tissue; 2) interface between bone and prosthesis; and 3) intramedullary (IM). Chi-square, Student's t-, and Wilcoxon Mann-Whitney U-tests were used as appropriate. Univariate and multivariate logistic regression analyses were performed to evaluate predictors of septic failure. RESULTS: Weight > 100 kilograms (P = .033), higher Charlson Comorbidity Index (P < .001), and positive IM cultures (P < .001) were associated with a higher risk of reinfection after one-stage revision TKA. A positive IM sample carried a nearly five-fold increase in odds of reinfection (odds ratio 4.86, 95% confidence interval 1.85 to 12.78, P = .001). CONCLUSIONS: A positive IM culture sample is significantly associated with septic failure after one-stage exchange for periprosthetic joint infection of the knee. Patients who had positive IM cultures may benefit from longer postoperative antibiotic therapy for the treatment of one-stage exchange arthroplasty to minimize the risk of reinfection.

Risk Factors and Microbiological Profile of Knee Periprosthetic Joint Infections With Sinus Tract.

BACKGROUND: A sinus tract is an abnormal channel that communicates between the skin and the joint, and meets one of the major criteria that is diagnostic of periprosthetic joint infection (PJI). The purpose of this study was to compare the risk factors and the microorganism profile of PJI of the knee with an overlying sinus tract to PJI without a sinus tract. METHODS: This was a retrospective case-control study of PJI following total knee arthroplasty with and without the presence of an overlying sinus tract from 1996 to 2020. There were 2,685 unique cases of chronic PJI following total knee arthroplasty, of which 405 cases (15.1%) had a sinus tract and 2,280 cases (84.9%) did not. Univariate and multivariate analyses were performed to evaluate risk factors and the microorganism profiles of the 2 groups. Odds ratios with 95% confidence intervals were reported. RESULTS: After adjusting for potential confounders in the multivariate analysis, the presence of a sinus tract was associated with a history of severe liver disease (P = .039; odds ratio: 1.99; 95% confidence interval: 1.04 to 3.84). Polymicrobial infections comprised 41.7% of PJI in the sinus tract group, compared to 29.1% in patients who did not have a sinus tract (P < .001). Of the monomicrobial PJI, Staphylococcus aureus (P < .001), Enterococcus faecalis (P < .001), Enterobacter cloacae (P = .002), Corynebacterium species (P = .037), Proteus mirabilis (P = .028), coagulase-negative Staphylococci (P = .019), and Candida albicans (P = .029) were more common in patients who had a sinus tract. CONCLUSIONS: The microbiology profile is significantly different in patients who have PJI of the knee with a sinus tract. These findings can guide the surgeon with surgical planning and selecting the appropriate antibiotic-loaded bone cement and empiric antibiotic treatment.

Increased Involvement of Staphylococcus epidermidis in the Rise of Polymicrobial Periprosthetic Joint Infections.

BACKGROUND: In this study, we aimed to analyze the temporal distribution of polymicrobial periprosthetic joint infections (PJIs), while also evaluating the patient risk factors associated with these infections following total joint arthroplasty at our institution across 2 distinct periods. METHOD: This retrospective cross-sectional study evaluated 259 patients who had knee or hip PJI from 2001 to 2006 and 2018 to 2022. A PJI was diagnosed using the 2018 International Consensus Meeting criteria. We utilized the Polymicrobial Pathogens' Co-occurrence Network Analysis, a novel approach that leverages network theory to map and quantify the complex interplay of organisms in PJIs. RESULTS: Of the 259 patients who had polymicrobial PJI, 58.7% were men, with mean age 67 years (range, 24 to 90). Of the 579 identified pathogens, Staphylococcus epidermidis was the most common (22.1%), followed by Staphylococcus aureus (9.0%) and Cutibacterium acnes (7.8%). The co-occurrence analysis indicated that Staphylococcus epidermidis frequently coexisted with Cutibacterium acnes (26 cultures) and Staphylococcus capitis (22 cultures). A notable increase in body mass index from 27.7 ± 4.4 in 2001 to 2006 to 29.7 ± 6.2 in 2018 to 2022 was observed (P = .001). Moreover, infections from Staphylococcus epidermidis, Cutibacterium acnes, and Staphylococcus capitis saw a significant uptick (P < .001). CONCLUSIONS: The study shows that from 2001 to 2022, there was a significant change in the pathogens responsible for polymicrobial PJIs, particularly an increase in Staphylococcus epidermidis, Cutibacterium acnes, and Staphylococcus capitis. Alongside these microbial changes, there was a rise in body mass index and shifts in comorbid conditions, such as more renal disease and fewer cases of congestive heart failure. These changes highlight the dynamic interplay between host and microbial factors in the pathogenesis of polymicrobial PJIs, necessitating adaptive strategies in both surgical and postoperative care to mitigate the rising tide of these complex infections.

Minimum 15-Year Survival of a Biconvex Inlay Patellar Component in Primary Total Knee Arthroplasty: An Analysis of 2,530 Total Knee Arthroplasties From a Single Institution.

BACKGROUND: Routine patellar resurfacing during primary total knee arthroplasty (TKA) remains controversial. To our knowledge, there are no studies reporting the long-term performance of a cemented biconvex all-polyethylene inlay component implanted at the time of primary TKA. The purpose of this study was to examine the 15-year survivorship and long-term clinical outcomes of this biconvex inlay patella used at our institution. METHODS: We retrospectively reviewed our prospectively collected institutional database and identified 2,530 patients who underwent cemented TKA with a single prosthetic design (from 1996 to 2007) where the patella was resurfaced using this cemented biconvex inlay patella. The mean age at surgery was 68 years (range, 29 to 93). The mean body mass index was 33.0 (range, 16.4 to 76.3), with 61.9% women. At the time of analysis, the mean time from surgery was 20.4 years (range, 15 to 26). We used Kaplan-Meier analysis to calculate survivorship at 15 years. We analyzed clinical outcomes using 3 patient-reported outcome measures collected prospectively. RESULTS: The 15-year survivorship with revision surgery for all causes as the end point was 97.1% (95% confidence interval 96.1 to 98.1%). The 15-year survivorship with revision surgery for a patella-related complication as the end point was 99.7% (95% confidence interval 99.4 to 1.0). At the final follow-up, patients showed significant improvement in scores for the Knee Society Clinical Rating System (P < .001), Western Ontario and McMaster University Osteoarthritis Index (P < .001), and Veterans Rand 12-Item Health Survey physical component (P < .001). CONCLUSIONS: Routine patellar resurfacing using a biconvex inlay patellar component has excellent survivorship and a low rate of complications at 15 years post-TKA.

How reliable is the soft tissue radiological knee index in predicting superficial surgical site infection following total knee arthroplasty?

INTRODUCTION: The purpose of this study was to evaluate the association between the Soft Tissue Radiological Knee (SToRK) Index and the risk of developing a superficial surgical site infection (SSSI) following primary total knee arthroplasty (TKA). METHODS: The SToRK Index was measured using calibrated long leg radiographs (LLR) in 174 patients undergoing TKA. RESULTS: A moderate correlation was found between the SToRK Index and body mass index (BMI) (rs=0.574; p < 0.001). The SToRK Index was a better predictor of SSSI in females than males. In females, a SToRK Index cutoff of 2.01 had a sensitivity and specificity of 41.3% and 74.6% for developing SSSI, respectively, with a positive likelihood ratio of 1.63. CONCLUSION: The SToRK Index can be used as an additional tool in assessing the risk for SSSI after TKA. It might be more predictive in females due to the different fat distribution compared to males.

Indirect Coronal Reduction Technique Using a Volar Locking Plate in Distal Radius Fractures: A Case Series.

This is a retrospective case series of patients with distal radius fractures treated with an indirect coronal reduction technique previously described by the senior author using volar locking plates. Seventeen distal radius fractures underwent treatment at a Level I Trauma Center and were retrospectively reviewed for anatomic alignment, surgical complications, and wrist range of motion in the global period. Near-anatomic restoration was achieved with the average radial inclination, radial height, and volar tilt measured as 23.2 ± 3.9 degrees, 11.8 ± 2.1 degrees, and 8.5 ± 5.4 degrees, respectively. Average coronal translation was 2.8 ± 2.7 mm. Postoperative wrist motion on average was within the normal ranges for pronation, supination, wrist flexion, and wrist extension at an average of 36 weeks follow-up. There were no complications related to surgical technique or implant. This case series demonstrates the reliability for coronal reduction with a volar locking plate technique without complications. (Journal of Surgical Orthopaedic Advances 33(1):037-040, 2024).

Comparison of Lateral versus Medial Entry Femoral Traction Pin Complication Rates.

Distal femoral skeletal traction is a common procedure for the stabilization of fractures of the pelvis, acetabulum, and femur following trauma. Femoral traction pins are traditionally inserted via medial-to-lateral (MTL) entry to accurately direct the pin away from the medial neurovascular bundle. Alternatively, cadaveric studies have demonstrated low risk to the neurovascular bundle using a lateral-to-medial (LTM) approach. The purpose of this study was to compare the incidence of complications of LTM and MTL femoral traction pin placement at a single institution. This was a retrospective review of patients from the orthopaedic consult registry at a academic Level I Trauma Center. We identified 233 LTM femoral traction pin procedures in 231 patients and 29 MTL pin procedures in 29 patients. The two pin placement techniques were compared with respect to complications, specifically the incidence of neurovascular injury, cellulitis, septic arthritis, osteomyelitis, and heterotopic ossification after femoral traction pin placement. Two complications were reported. One patient developed heterotopic ossification along the pin tract after LTM traction pin placement. Another patient developed septic arthritis after LTM pin placement, likely attributable to retrograde intramedullary nailing of his open femur fracture rather than his traction pin. There were no reports of neurovascular injury, cellulitis, or osteomyelitis associated with pin placement. The complication rate was 0.9% for LTM group and 0.0% for MTL group (p = 0.616). LTM femoral traction pin placement is a safe procedure with a similarly low complication rate compared with traditional MTL placement when the limb is positioned in neutral alignment. (Journal of Surgical Orthopaedic Advances 32(4):259-262, 2023).

Hip Arthroscopic Microfracture Augmented With Platelet-Rich Plasma-Infused Micronized Cartilage Allograft Significantly Improves Functional Outcomes.

PURPOSE: To evaluate functional outcomes and survivorship in patients at 1 year after undergoing arthroscopic microfracture augmented with hyaline allograft for symptomatic chondral defects of the hip. METHODS: Consecutive patients with and without prior hip procedures presenting with Outerbridge grade IV chondral lesion of the acetabulum or femoral head were prospectively followed. Patients underwent hip microfracture augmented with hyaline allograft suspended in autologous platelet-rich plasma between October 2016 and April 2018. Extent of cartilage degeneration was quantified using the chondromalacia severity index (CMI). Patient functional scores, including Tegner, Hip Outcome Score-Activities of Daily Living (HOS-ADL), Sport-Specific Subscale (HOS-SSS), modified Harris Hip Score (mHHS), and Nonarthritic Hip Score (NAHS) were collected preoperatively and at minimum 1-year postoperatively. Minimal clinically important difference (MCID) was analyzed. Statistical significance was established at P < .05. Pearson's coefficient analysis was performed to identify preoperative variables correlated with clinical outcomes. RESULTS: Fifty-seven patients (86.4%) had minimum 1-year follow-up and were included in the final analysis, with a mean age and body mass index (BMI) of 38.3 ± 9.1 years and 27.7 ± 4.9 kg/m2, respectively. Comparison of baseline and postoperative score averages demonstrated significant improvements in Tegner scores (3.7 ± 2.9 vs 5.1 ± 2.6; P = .003), HOS-ADL (63.3 ± 16.4 vs 89.1 ± 14.5; P < .001), HOS-SSS (40.8 ± 20.4 vs 79.5 ± 21.6; P < .001), mHHS (61.5 ± 16.2 vs 87.0 ± 17.7; P < .001), and NAHS (56.6 ± 14.9 vs 78.7 ± 18.3; P < .001). The percentage of patients who achieved MCID for HOS-ADL, HOS-SSS, mHHS, and NAHS were 89.8%, 83.0%, 75.6%, and 81.6%, respectively. Overall, 91.8% of patients met the threshold for achieving MCID in at least one outcome score. Of the 57 patients, 5 (8.8%) failed clinically, with 1 (1.8%) undergoing revision surgery and 4 (6.9%) undergoing conversion to total hip arthroplasty. There was a direct correlation between preoperative alpha angle and postoperative HOS-ADL. Femoral chondral lesion size and CMI inversely correlated with postoperative HOS-ADL. CONCLUSIONS: Treatment of hip chondral defects with microfracture and hyaline allograft augmentation demonstrated excellent survivorship and significantly improved patient report outcomes at 1 year. LEVEL OF EVIDENCE: IV, retrospective case series.

Dually Insured Medicare/Medicaid Patients Undergoing Primary TJA Have More Comorbidities, Higher Complication Rates, and Lower Reimbursements Compared to Privately Insured Patients.

BACKGROUND: Dual eligibility status (DES: qualifying for both Medicare and a Medicaid supplement) was recently proposed by the Center for Medicare and Medicaid Services as a socioeconomic qualifier for risk adjustment in primary total joint arthroplasty. However, the profile and outcomes of DES patients have never been compared to privately insured patients. METHODS: A retrospective case-control study of the Mariner database within the PearlDiver server between 2010 and 2017 was performed. Patients aged 60 to 80 undergoing primary total hip arthroplasty (THA) and total knee arthroplasty (TKA) (separately) were stratified based upon payer type: DES versus private payer. A propensity score-matched analysis with nearest neighbor pairing (1:1 ratio) was performed to compare 90-day outcomes and reimbursements. RESULTS: A total of 315,664 private and 3961 DES THA patients and 670,899 private and 2255 DES TKA patients were identified. DES patients were older and had a greater prevalence of comorbidities (31/36, P < .001). The THA DES matched cohort had greater transfusion rates (6.8% versus 3.9%, P < .001), higher 90-day emergency department visits (22.8% versus 16.3%, P < .001) and readmissions (16.8% versus 9.5%, P < .001), and lower reimbursements ($19,615 versus $13,036, P < .001). The TKA DES matched cohort had more cardiac events (0.4% versus 0.09%, P = .03), emergency department visits (25.2% versus 19.9%, P < .001), readmissions (14.4% versus 11.2%, P = .001), and reoperations (0.85% versus 0.35%, P = .03) CONCLUSION: DES patients have different comorbidity profiles, and even after propensity score matching have a greater risk of complications and are reimbursed less compared to privately insured patients. In the setting of alternative payment models, these differences should be accounted for through risk adjustment.

An Innovative Seven-year Physician Scientist Residency Training Program That Addresses the Shortage of Academic Surgeons.

Due to the declining number of scientifically trained physicians and increasing demand for high-quality literature, our institution pioneered a seven-year Physician Scientist Training Program (PSTP) to provide research-oriented residents the knowledge and skills for a successful academic career. The present study sought to identify orthopaedic surgeons with MD/PhD degrees, residency programs with dedicated research tracks, and to assess the effectiveness of the novel seven-year program in training prospective academic orthopaedic surgeons. Surgeons with MD/PhD degrees account for 2.3% of all 3,408 orthopaedic faculty positions in U.S. residency programs. During the last 23 years, our PSTP residents produced 752 peer-reviewed publications and received $349,354 from 23 resident-authored extramural grants. Eleven of our seven-year alumni practice orthopaedic surgery in an academic setting. The seven-year PSTP successfully develops clinically trained surgeon scientists with refined skills in basic science and clinical experimental design, grant proposals, scientific presentations, and manuscript preparation. (Journal of Surgical Orthopaedic Advances 31(3):144-149, 2022).

Noise Exposure and Risk of Noise Induced Hearing Loss to the Adult Reconstruction Surgeon: Recommendations for Prevention and Monitoring.

Goal of the study was to determine the average noise exposure to the orthopaedic surgeon performing hip and knee arthroplasty and the benefit of customized hearing protection. Data from dosimeters (3MTM Edge 4) worn by three adult reconstruction orthopedic surgeons for a total of 27 operative day recordings was analyzed using 3MTM Detection Management Software (product version 2.7.152.0). Westone TRU custom hearing protection was used with different filters according to noise reduction rating (NRR). The overall average decibel level was 80.64 dB (73.6-87.2 dB, +/- 4.18). The peak decibel level averaged 103.66 dB (97.30-110.30, +/-3.02). The authors subjective trial of custom hearing protection determined the NRR 10 and 15 filters were most effective at noise reduction with adequate ability to communicate effectively. Our study demonstrates that the daily exposure to the total joint surgeon exceeds safe levels. (Journal of Surgical Orthopaedic Advances 29(4):202-204, 2020).

Complications and Costs Are Not Increased After Total Hip Arthroplasty in Patients With a History of Prostate Cancer.

BACKGROUND: Prostate cancer (PCa) is a largely prevalent disease in the United States. Moreover, it is unclear whether the thromboembolic burden of disease remains present after the cancer has been treated and whether such state impacts the short-term outcomes of orthopedic procedures. Therefore, the purpose of this study is to assess 90-day postoperative complications and costs after total hip arthroplasty (THA) for osteoarthritis in patients with a history of PCa. METHODS: Two groups of patients who underwent THA for osteoarthritis in the Medicare Standard Analytical Files were identified through the PearlDiver server. Both groups were matched based on age, diabetes, smoking status, chronic kidney disease, alcohol abuse, chronic liver disease, and obesity in order to create a case-control study comparison. The 90-day complication rates after THA were compared using univariate regressions (odds ratio). We hypothesized that patients with a history of PCa would develop increased rates of thromboembolic complications based on a prolonged procoagulative state. RESULTS: After matching, each group was comprised of 62,571 patients. Our findings identified greater 90-day pneumonia rates for those without a history of PCa (3.26% vs 2.68%; odds ratio, 0.82). All other complications including thromboembolic diseases were clinically comparable in both groups during the 90-day postoperative period. The charges and reimbursements for the 90-day period were also comparable. CONCLUSION: In our large case-control study of 125,142 patients, we found that patients with a history of PCa do not have increased risk of short-term complications after THA and that the mean 90-day reimbursements were similar for both groups at $14,153 for PCa patients and $14,033 for those without (P = .114).

Epidural Abscess in the Lumbar Spine: A Single Institution's Experience With Nonsurgical and Surgical Management.

The purpose of this study was to compare patient factors and outcomes in conservatively and surgically treated patients with spinal epidural abscess (SEA). This was a single-center retrospective review of adult patients treated for SEA of the lumbar spine. Primary treatment outcome was readmission for recurrent abscess. Sixty-one patients met inclusion criteria: 59% male, mean age 56.9 years, and body mass index 30.8 kg/m2. Initially 47.5% of patients were treated with conservative measures and 52.5% were treated with surgery. In the conservative group, 31.0% failed treatment and underwent delayed surgery; 26.2% of the overall cohort was readmitted for SEA. Readmitted patients had a greater incidence of history of methicillin-resistant Staphylococcus aureus (p = .048), recurrent infections (p = .008), and recent sepsis and bacteremia (p = .005). Nearly one-third of patients failed initial conservative treatment and needed delayed surgery; however, no significant differences were found between the two treatment groups. Patients with a past history of infections may require more aggressive treatment and closer follow-up, because they are at higher risk for recurrence and readmission. (Journal of Surgical Orthopaedic Advances 28(3):224-231, 2019).

Peripheral Nerve Injury After Elbow Arthroscopy: An Analysis of Risk Factors.

PURPOSE: To identify risk factors associated with peripheral nerve injury after elbow arthroscopy and provide an updated incidence of those complications. METHODS: The elbow arthroscopies that were performed at our institution between 2006 and 2016 were identified. Over a 10-year period, 253 elbow arthroscopies were performed at our institution. Two hundred twenty-seven cases had a minimum follow-up of 4 weeks, and were included in our analysis. Minor and major nerve-related complications were recorded. The surgeon's experience and training, body max index of the patients, surgical tourniquet time, type of anesthesia or surgery, radiographic appearance of the elbow, diagnosis at the time of surgery, and presence of diabetes were analyzed. RESULTS: There were 12 reported peripheral nerve injuries, 10 minor (4.4%) and 2 major complications (0.9%). The risk factors examined in this study were not correlated with a higher rate of complications. CONCLUSIONS: The minor nerve-related complication rate was 4.4%, with a 0.9% incidence of major peripheral nerve injury. Based on these findings, we conclude that elbow arthroscopy is a relatively safe procedure. The risk factors examined in this study had no association with the rate of complications. This finding could be potentially related to type II or beta error in the analysis of risk factors for nerve injury. The exact reasons for nerve injury are not known from this study. LEVEL OF EVIDENCE: Level IV, retrospective case series.

Anatomical Factors Contributing to Radial Nerve Excursion at the Brachium: A Cadaveric Study.

PURPOSE: The radial nerve appears to be more vulnerable to injury in the brachium than the median and ulnar nerves. The underlying mechanism for this increased vulnerability is not well explained. We hypothesize that the radial nerve has less excursion than the median and ulnar nerves because it is anatomically tethered by the lateral intermuscular septum (LIS) and that elbow positioning and LIS release will improve its excursion. METHODS: Eight paired fresh-frozen cadaveric upper extremity specimens were used. The radial, median, and ulnar nerves were transected at the level of the spiral groove. Nerve excursion was determined at a constant tension of 100 g from 0° to 90° of elbow flexion and repeated for the radial nerve after releasing the LIS. The cross-sectional areas of nervous and connective tissue were then determined histologically. RESULTS: Radial and median nerve excursion correlated positively with increased elbow flexion, and ulnar nerve excursion correlated negatively with increased elbow flexion. Release of the LIS significantly improved radial nerve excursion at 0°, 60°, and 90° of elbow flexion. Release of the LIS with 90° of elbow flexion increased radial nerve excursion by approximately 3 times. Histological analysis demonstrated similar mean composition of nonnervous connective tissue among the 3 nerves. CONCLUSIONS: The radial nerve is anatomically tethered in the brachium by the LIS and has limited excursion compared with the median and ulnar nerves. Radial nerve excursion improves with elbow flexion and LIS release. Flexing the elbow to 90° doubles radial nerve excursion. Releasing the LIS as well triples the excursion of the radial nerve. Histological composition was similar among the three nerves at the brachium. CLINICAL RELEVANCE: Releasing the LIS and flexing the elbow improve radial nerve excursion. These steps may be useful during humeral fracture fixation.

Medium-Term Outcomes With Pyrocarbon Proximal Interphalangeal Arthroplasty: A Study of 170 Consecutive Arthroplasties.

PURPOSE: The purpose of this study was to examine the medium-term outcomes of patients undergoing proximal interphalangeal (PIP) joint arthroplasty using a pyrocarbon implant. METHODS: The study comprised an analysis of 170 PIP joint pyrocarbon arthroplasties in 99 patients with a minimum 2-year clinical follow-up. Diagnoses included inflammatory arthritis (n = 49), posttraumatic arthritis (n = 29), and osteoarthritis (n = 92). Univariate logistic regression and Kaplan-Meier survival analyses were performed. RESULTS: At an average follow-up of 6 years (range, 2-14 years), 58 reoperations (34%) were required, including 36 (21%) involving implant revision surgery. The majority of revisions were performed for either dislocations (n = 16) or pain and stiffness (n = 14). The 5- and 10-year survival-free of revision surgery rates were 79% and 77%, respectively. The risk for revision surgery was higher in patients with posttraumatic arthritis. There were 15 intraoperative complications involving a fracture and 26 postoperative complications, including 21 dislocations. In unrevised implants, patients had significant improvements in their preoperative to postoperative pain levels, with no change in their PIP joint total arc of motion. At a mean radiographic follow-up of 5.4 years, there were 28% with grade 3+ loosening and 36% with progressive implant instability. Implant loosening or progressive instability was not associated with worse pain or PIP joint total arc of motion. CONCLUSIONS: Approximately 1 in 5 PIP joint arthroplasties with a pyrocarbon implant will require revision surgery by 5 years, and 1 in 3 will undergo more than 1 operation. Furthermore, 1 in 4 PIP joint arthroplasties will have grade 3+ radiographic loosening and 1 in 3 will have progressive loosening or subsidence by 5 years. These results are particularly concerning in young patients and those with posttraumatic arthritis. Overall, in patients that do not require revision surgery, pain relief was improved and motion maintained. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Transfer of the Dorsal Cutaneous Branch of the Ulnar Nerve for Restoration of Median Nerve Sensation: A Cadaveric Study.

The use of dorsal cutaneous branch of the ulnar nerve (DCBUN) transfer for median nerve (MN) sensory restoration has not been evaluated anatomically and histologically in humans. The purpose of this study was to evaluate the feasibility of DCBUN to MN transfer for sensory restoration with respect to nerve branch pattern, length, and fascicle count match.Using seven fresh frozen cadaveric upper limb specimens, the DCBUN and its branch patterns, lengths, and sizes were recorded. The MN was exposed within the carpal tunnel and dissected distally to identify the common digital nerves (CDN). Simulated nerve transfer was performed with palmar coaptation of the DCBUN branches with the CDNs. Histological analysis of each nerve branch was performed. The seven specimens had a mean of 3.57 branches (range 2-4) off the DCBUN. The longest branch innervated the dorsal 4th web space, on average reaching 7.6 cm distal to the wrist crease. Transferring the DCBUN branches palmarly did not substantially change their maximum distance distal to the wrist crease. The MN CDNs and DCBUN branches had mean cross-sectional areas of 6.37 and 1.99 mm2 , respectively, and mean fascicle counts of 10.4 and 4.05, respectively. The DCBUN provides 2-4 branches suitable for tension-free end-to-end transfer to the MN CDNs. The individual size of the DCBUN branch is smaller than CDN; however, combining two or more branches of the DCBUN would overcome the fascicle and size mismatch to reconstruct the 1st web space CDN for critical sensory restoration. Clin. Anat. 31:1006-1012, 2018. © 2018 Wiley Periodicals, Inc.

Coronal Plane Deformity Correction in Distal Radius Fracture Fixation With the Volar Locking Plate.

The goal of treatment for distal radius fractures is anatomic articular reduction and restoration of coronal and sagittal plane alignment, rotation, and angulation of the metadiaphyseal component of these fractures. This article presents a reproducible technique for restoring coronal plane alignment of the metadiaphyseal component of the fracture using an indirect reduction maneuver leveraging the volar locking plate as an indirect reduction aid. After applying an appropriately sized volar locking plate, the first screw is placed in the center of the shaft of the plate. Next, the distal row of subarticular locking screws is placed to neutralize a reduced articular surface. The shaft screw is subsequently loosened, and two Freer elevators are used to rotate the plate, indirectly translating the distal articular block and achieving improved coronal plane alignment. Last, the remaining diaphyseal screws are applied to appropriately neutralize the fracture. (Journal of Surgical Orthopaedic Advances 27(2):160-163, 2018).

Effects of age and insulin-like growth factor-1 on rat neurotrophin receptor expression after nerve injury.

INTRODUCTION: Neurotrophin receptors, such as p75(NTR) , direct neuronal response to injury. Insulin-like growth factor-1 receptor (IGF-1R) mediates the increase in p75(NTR) during aging. The aim of this study was to examine the effect of aging and insulin-like growth factor-1 (IGF-1) treatment on recovery after peripheral nerve injury. METHODS: Young and aged rats underwent tibial nerve transection with either local saline or IGF-1 treatment. Neurotrophin receptor mRNA and protein expression were quantified. RESULTS: Aged rats expressed elevated baseline IGF-1R (34% higher, P = 0.01) and p75(NTR) (68% higher, P < 0.01) compared with young rats. Post-injury, aged animals expressed significantly higher p75(NTR) levels (68.5% above baseline at 4 weeks). IGF-1 treatment suppressed p75(NTR) gene expression at 4 weeks (17.2% above baseline, P = 0.002) post-injury. CONCLUSIONS: Local IGF-1 treatment reverses age-related declines in recovery after peripheral nerve injuries by suppressing p75(NTR) upregulation and pro-apoptotic complexes. IGF-1 may be considered a viable adjuvant therapy to current treatment modalities. Muscle Nerve 54: 769-775, 2016.