Dynamic Tendon Grip (DTG™) novel knot array compared to traditional sutures for zone two flexor tendon injury - a biomechanical feasibility study.

BACKGROUND: Flexor tendon injuries pose many challenges for the treating surgeon, the principal of which is creating a strong enough repair to allow early active motion, preserving a low-profile of the repair to prevent buckling and subsequent pulley venting. A main concern is that a low-profile repair is prone to gap formation and repair failure. The Dynamic Tendon Grip (DTG™) all suture staple device claims to allow a strong and low-profile repair of the flexor tendon. The purpose of this study is to test the effects of the DTG™ device in early active motion simulation on range of motion, load to failure and gap formation and to compare it to traditional suturing technique. METHODS: Twelve fresh-frozen cadaveric fingers were assigned to two groups: DTG™ device (n = 9) and traditional suturing (double Kessler 4-core suture and a peripheral suture, n = 3). The deep flexor was incised and repaired in zone 2, and active motion simulation was carried out with a cyclic flexion-extension machine. Finger range of motion and gap formation were measured, as well as load to failure and method of repair failure. RESULTS: Following motion simulation, ROM decreased from 244.0 ± 9.9° to 234.5 ± 5.8° for the DTG™ device compared to 234.67 ± 6.51° to 211.67 ± 10.50° for traditional suturing. The DTG™ repair demonstrated gap formation of 0.93 ± 0.18 mm in 3 of 8 specimens after applying 1 kg load, which negated after load removal. Load to failure averaged 76.51 ± 23.15 N for DTG™ and 66.31 ± 40.22 N for the traditional repair. Repair failure occurred as the suture material broke for the DTG™ array and at the knot level for the traditional repair. CONCLUSIONS: The DTG™ all-suture stapling concept achieved a strong low-profile repair in zone 2 flexor tendon injury after active motion simulation. Further clinical studies will be needed to determine the effectiveness of this device compared to traditional techniques.

Overutilization of Radiographs for Pulled Elbow Among Orthopedic Surgeons Compared With Pediatricians.

METHODS: Electronic medical records of the largest health provider in Israel, which provides health services to more than 50% of the population, were reviewed for pulled elbow cases between 2005 and 2020. Patients aged 4.5 months to 7 years were included. Demographic information, the discipline of the treating physician, and acquisition of elbow radiographs were gathered. RESULTS: A total of 4357 patients, 62.8% girls, were included. The average body mass index was 16.1 (SD, 1.2). Most patients were from communities in the upper half of the socioeconomic status clusters 6 to 10 (64.63%). Most patients were attended by a pediatrician (51.5%), followed by an orthopedic surgeon (19.9%). Radiographs were acquired for 570 children (13.1%). Most radiographs (36.5%) were requested by orthopedic surgeons and for children in the boundary age groups. The patient's socioeconomic status was associated with access to physicians of different subspecialties, and lower income families had a higher tendency to be treated by nonspecialized physician ( P < 0.001). CONCLUSIONS: Orthopedic surgeons use elbow radiographs much more than pediatricians; effort should aim at reducing the imaging rate for this population.

Use of Thermoplastic Rings Following Venting of Flexor Tendon Pulleys: A Biomechanical Analysis.

PURPOSE: Normal digital flexion relies on flexor tendon pulleys to convert linear muscular force to angular digital motion. However, there is a growing trend to vent them partially during flexor tendon repair. The objective of this study was to examine the effects of a thermoplastic ring, acting as an external pulley, on flexor tendon biomechanics and finger range of motion (ROM) after pulley venting. METHODS: We tested 15 cadaveric digits using an in vitro active finger motion simulator. We measured loads induced by flexor digitorum superficialis (FDS) and flexor digitorum profundus (FDP) as well as joint ROM with sequential sectioning of the A2, A3, and A4 pulleys compared with an intact pulley condition. At each stage, external thermoplastic pulley rings were applied snugly over the proximal and middle phalanges to recreate A2 and A4 function, respectively. RESULTS: After complete venting of the A2, A3, and A4 pulleys, proximal interphalangeal joint ROM significantly decreased by 13.4° ± 2.7° and distal interphalangeal joint ROM decreased by 15.8° ± 2.1°. Application of external rings over the proximal and middle phalanx resulted in a residual ROM decrease of 8.3° ± 1.9° at the proximal interphalangeal joint and 7.9° ± 2.1° at the distal interphalangeal joint, nearly restoring ROM. Similarly, complete pulley venting resulted in reduced FDS load by 37% and FDP load by 50% compared with intact pulleys. After application of external rings, loads were restored almost to normal, with a 9% reduction for FDS load and 9% reduction for FDP load compared with intact pulleys. CONCLUSIONS: The application of thermoplastic rings acting as external pulleys is an effective, noninvasive, and reproducible approach to restore flexor tendon biomechanics and digit ROM after pulley venting. CLINICAL RELEVANCE: Thermoplastic rings may be a useful therapeutic adjunct in restoring joint ROM and flexor tendon loads after surgical venting of the pulleys.

Safe Zones for Cerclage Wiring of the Humeral Diaphysis.

Cerclage wiring of the humeral diaphysis entails particular danger to the radial nerve and the deep brachial artery. We sought to delineate safe zones for minimally invasive cerclage wiring of the humeral diaphysis, specifically in relation to the radial nerve and accompanying vasculature. Cerclage wires were percutaneously inserted into three groups of fresh-frozen cadaveric humeri. Group 1-proximal midshaft humerus at 30% of humeral height (n = 4); Group 2-midshaft spiral groove at 45% of humeral height (n = 4); and Group 3-distal midshaft humerus at 60% of humeral height (n = 4). Subsequently, an extensive surgical exploration of the arteries and nerves around the humerus was performed, noting any disturbance to the vessels or nerves and measuring the distance from the cerclage wire to the radial nerve. Neurovascular structures were injured in 75% of specimens when the cerclage wire was inserted at the level of the spiral groove. Both posterior structures, e.g. the radial nerve and the deep brachial artery, and medial structures, e.g., the median nerve and brachial artery, were incarcerated. Application of the cerclage at 30% or 60% of humeral height did not cause neurovascular injury. Minimally invasive application of the cerclage wire at the spiral groove, which is at 45% of humeral height, is likely to cause injury to neurovascular structures. Application of the cerclage at the proximal or distal midshaft humeral areas is associated with less risk of such injury. Clin. Anat. 33:552-557, 2020. © 2019 Wiley Periodicals, Inc.

3D imaging and stealth navigation instead of CT guidance for radiofrequency ablation of osteoid osteomas: a series of 52 patients.

BACKGROUND: Osteoid osteomas are benign bone neoplasms that may cause severe pain and limit function. They are commonly treated by radiofrequency ablation (RFA) through a needle inserted into the nidus of the lesion under CT guidance, which is associated with exposure of young patients to relatively high dose of radiation. The objective of this study was to investigate the amount of radiation, effectiveness and safety of an alternative imaging approach, the 3D image-guided (O-arm) technology and the Stealth navigation. METHODS: We retrospectively reviewed 52 electronic medical files of patients (mean age 24.7 years, range 8-59 years) who were treated with thermal ablation of benign osteoid osteomas guided by the navigated O-arm-assisted technique in our institution between 2015 and 2017. Data were extracted on the associated complications, the reduction in pain at 3 months and one year postoperatively, and the amount of radiation administered during the procedure. RESULTS: The level of pain on a visual analogue scale decreased from the preoperative average of 7.73 to 0 at the 3-month follow-up. The mean dose-length product was 544.7 mGycm2 compared to the reported radiation exposure of 1971-7946 mGycm2 of CT-guided radio ablations. The one intra-operative complication was a superficial burn in the subcutaneous lesion in a tibia that was treated locally with no major influence on recovery. CONCLUSIONS: RFA ablation guided by 3D O-arm stealth navigation is as effective as the traditional CT-guided technique with the advantage of lower radiation exposure. TRIAL REGISTRATION: Retrospective study number 0388-17-TLV at Tel Aviv Sourasky Medical Center IRB, approved at 25.10.17.

The Vascular Anatomy of the Scaphoid: New Discoveries Using Micro-Computed Tomography Imaging.

PURPOSE: The purpose of this study was to investigate the intraosseous vascular anatomy of the scaphoid using recent advances in micro-computed tomography (micro-CT) imaging and 3-dimensional reconstruction. We also studied the effect of scaphoid shape and screw position on the intraosseous vascular structure. METHODS: Thirteen upper extremities were injected with a contrast agent. The scaphoid bones were extracted and scanned using a micro-CT scanner. The vascular impact of screw insertion at various axes through the scaphoid was calculated and compared using the generated 3-dimensional models. The specimens were 3-dimensionally-printed and the morphology was assessed according to bone dimensions. A relationship between the internal vascular patterns and these morphological features was determined. RESULTS: All specimens received vascular inflow from the dorsal ridge forming a vascular network that supplied an average of 83% of the bone's volume. This network was supplemented in 4 specimens with volar vessels entering at the waist. Another network was identified, created by vessels entering volarly at the tubercle, which supplied the remainder of the scaphoid. One specimen did not receive any vessels at the tubercle. With regards to screw placement, screws placed in the central axis were the least disruptive to the internal vascularity, followed by the antegrade (dorsal) insertion axis. Two morphological bone types were identified: type I or full scaphoids and type II or slender scaphoids. Type I possessed a more robust internal vascular network than type II scaphoids. CONCLUSIONS: This study identifies 2 distinct types of scaphoid morphology with 1 of them having a less robust blood supply, which may prove to be related to development of nonunion, avascular necrosis, or Preiser disease. Central axis and antegrade (dorsal) screw fixation may be least disruptive to the internal blood supply. CLINICAL RELEVANCE: Safer fixation of the scaphoid bone may be achieved by knowledge of intraosseous vascular patterns.

Displaced distal radius fracture presenting with neuropraxia of the dorsal cutaneous branch of the ulnar nerve (DCBUN).

Nerve injuries, mostly to the median nerve, are common following distal radius fractures. Ulnar nerve injuries are rarely encountered, with only few case reports of motor or motor and sensory loss described in the literature. In this paper, we report two consecutive cases of young patients with a distal radius fracture and a pure sensory ulnar neuropathy. Both patients had a radially displaced fracture and presented with sensory loss and paresthesia in the distribution of the dorsal cutaneous branch of the ulnar nerve (DCBUN), which resolved after fracture reduction. We believe this clinical scenario is the result of traction or compressive neuropraxia of the DCBUN in the subcutaneous tissue around the ulnar styloid-a neurologic injury which had not yet been described for distal radius fractures.

Manipulation under anesthesia for the postsurgical stiff elbow: a case series and review of literature.

INTRODUCTION: Elbow joint stiffness is a common complication following elbow trauma or surgery. Current practices include first-line treatment with physiotherapy and various types of splints. In cases where early postoperative loss of elbow motion interferes with activities of daily living, manipulation under anesthesia (MUA) is considered a viable treatment option, but there is currently only limited data on the results of this procedure and its complications. MATERIALS AND METHODS: This retrospective study was comprised of 12 consecutive patients who underwent MUA for the treatment of postsurgical elbow stiffness in one institution between 2010 and 2017. Their pre- and post-manipulation range of motion and their functional scores were assessed. RESULTS: MUA was performed at a mean of 52 days (range 39-91 days) following the last surgical intervention, and the patients were followed for a mean of 3 years (range 0.75-7 years). The average flexion-extension arc of motion improved by 53.8°, and the average rotation arc improved by 57°. The average Mayo Elbow Performance Score was 73 (range 0-100) at the latest follow-up. Two patients eventually underwent an open elbow contracture release due to poor post-manipulation results. There were no post-MUA complications. CONCLUSIONS: MUA of a postoperative stiff elbow can improve both flexion-extension and rotatory arc of motion in cases of early evolving postoperative stiffness and should be part of the armamentarium for the treatment of this often debilitating condition.

Multiple Enchondromas of the Hand in Children: Long-Term Follow-Up of Mean 15.4 Years.

BACKGROUND: Multiple enchodromatosis of bone, termed Ollier's disease, or Maffucci syndrome when associated with hemangiomas, is a rare disease that can affect the pediatric hand. This condition often causes a finger mass, deformity, pain and possible pathologic fractures, and has been associated with malignant transformation to chondrosarcoma. The aim of our study is to describe the long-term sequela of multiple enchondromatosis of the hand in the pediatric population, specifically the rates of malignant transformation, tumor recurrence, rates of pathologic fracture, and phalangeal growth arrest. METHODS: We examined 15 pediatric patients who were treated in our institute with a total of 127 phalanges and metacarpals lesions. Only patients with follow-up of at least 4 years were included. We retrospectively reviewed patients' chart and hand radiograph for symptoms including pathologic fractures, indications for surgery, and postoperative complications including tumor recurrence, and malignant transformation. We assessed phalangeal growth arrest with radiographs and normalized phalangeal growth charts. RESULTS: Mean age of diagnosis was 5.8 years and mean follow-up time was 15.4 years. Pathologic fractures were common at 46% of pediatric patients, but ceased to occur once reaching adulthood. Outcomes of pathologic fractures were excellent, regardless of treatment. Malignant transformation occurred in 1 patient and did not occur during childhood. A total of 80% of patients and 29% of lesions underwent surgical treatment of curettage and bone graft for the lesion, yet recurrence was common and affected 33% of treated patients. Phalangeal growth arrest was the most common long-term sequela and affected 11% of phalanxes and metacarpals. This sequela was significantly more prevalent in patients who had surgical excision of the tumor. CONCLUSIONS: Our findings reassure that malignant transformation of enchodromatosis of the hand is unlikely in the pediatric population. Pathologic fracture is common, but has excellent outcomes. When considering surgery, parents should be counseled about the possibility of phalangeal growth arrest and recurrence of the lesion. TYPE OF STUDY/LEVEL OF EVIDENCE: Level IV-therapeutic.

Repeated closed reduction attempts of distal radius fractures in the emergency department.

INTRODUCTION: Repeated attempts of closed reduction of distal radius fractures (DRF) are performed in the emergency department setting to optimize fracture alignment and avoid surgery. The additional manipulation of the fracture may, however, increase dorsal comminution and lead to loss of reduction in the cast. This retrospective cohort study has investigated the effect of second reduction attempt on fracture alignment and comminution. MATERIALS AND METHODS: Six-hundred-eighteen patients with DRF were treated in the medical center in 2007-2010. Seventy-six (12.3%) DRF who underwent two reductions were included in the study. Radiographs taken after the first and second reduction attempts were reviewed for changes in fracture alignment parameters (radial height, radial inclination, volar tilt) and dorsal comminution length. Patients were also followed retrospectively to determine the rates of secondary displacement in a cast. RESULTS: A second closed reduction attempt improved mean radial height by 1.43 mm, mean radial inclination by 1.62° and mean volar tilt by 8.75°. Mean dorsal comminution length increased by 1.6 mm. Of the 19 (25%) patients with acceptable alignments after two reduction attempts, follow-up radiographs were available for 12, which showed successful reduction in four cases (33.3 or 5.2% of total 76 patients). CONCLUSIONS: A second closed reduction attempt improved immediate fracture alignment, but also worsened dorsal comminution. Only 5.2% of patients who underwent two reduction attempts had an acceptable final alignment and did not require surgery. Increased dorsal comminution may further compromise fracture stability, complicate surgery and have negative effect on the postoperative course.

Functional outcomes after removal of hardware in patellar fracture: are we helping our patients?

PURPOSE: Functional outcomes after Open Reduction Internal Fixation (ORIF) of the patella are variable. Common complications of patella ORIF include persistent anterior knee pain, limited range of motion and symptomatic hardware. The purpose of this study was to evaluate if removal of hardware is beneficial to symptomatic patients after patellar fracture fixation. METHODS: Patients who presented to our institution between December 2006 and November 2014 with patella fractures treated with ORIF were eligible for inclusion. Patella ORIF was performed using (1) K-wires (KW) with a tension band construct or (2) Cannulated Screws (CS) with a tension band construct. Radiological analyses included (1) AO classification and (2) measurements of prominent hardware length. Patient medical charts were reviewed for demographic and intraoperative data as well as peri/postoperative complications. All patients completed the SF-12 score, visual analog scale, Kujala score, Lysholm score and questionaries' regarding return to previous activity levels. RESULTS: Forty-seven patients met the inclusion criteria. The average time from fracture fixation to removal of hardware was 15.8 (SD ± 14.9) months. The mean follow-up was 43.1 (SD ± 27.1) months. Patella fixation was accomplished using tension band constructs with KW in 28 patients (59.5%) or with CS in 19 patients (40.5%). Patient reported quality of life and pain outcomes improved significantly after removal of hardware (p = 0.001, and p = 0.002 respectively). Functional outcome scores (Kujala and Lysholm) did not improve significantly after hardware removal in the KW or CS groups. Significantly more patients in the KW group returned to pre-injury activity (p = 0.005). CONCLUSIONS: Hardware removal after patella ORIF significantly improves patient reported pain and quality of life outcomes but not functional outcomes. Patients should be counseled regarding the expected outcome of hardware removal following patella ORIF and diabetic patients should be given special consideration before undergoing this procedure.

Turkey model for flexor tendon research: in vitro comparison of human, canine, turkey, and chicken tendons.

BACKGROUND: Flexor tendon injuries are one of the most common hand injuries and remain clinically challenging for functional restoration. Canine and chicken have been the most commonly used animal models for flexor tendon-related research but possess several disadvantages. The purpose of this study was to explore a potential turkey model for flexor tendon research. METHODS: The third digit from human cadaveric hands, canine forepaws, turkey foot, and chicken foot were used for this study. Six digits in each of four species were studied in detail, comparing anatomy of the flexor apparatus, joint range of motion tendon excursion, tendon cross-sectional area, work of flexion, gliding resistance at the level of the A2 pulley, modulus of elasticity, suture retention strength, and histology across species. RESULTS: Anatomically, the third digit in the four species displayed structural similarities; however, the tendon cross-sectional area of the turkey and human were similar and larger than canine and chicken. Furthermore, the turkey digit resembles the human's finger with the lack of webbing between digits, similar vascularization, tendon excursion, work of flexion, gliding resistance, mechanical properties, and suture holding strength. More importantly, human and turkey tendons were most similar in histological appearance. CONCLUSIONS: Turkey flexor tendons have many properties that are comparable to human flexor tendons which would provide a clinically relevant, economical, nonhuman companion large animal model for flexor tendon research.

The Vascular Anatomy of the Capitate: New Discoveries Using Micro-Computed Tomography Imaging.

PURPOSE: To study the intraosseous 3-dimensional microvasculature of the capitate bone using a novel high-resolution micro-computed tomography (µCT) imaging technology, and to examine the blood supply as it relates to the most common fracture types. METHODS: Ten cadaveric wrists were injected with a lead-based contrast agent. The capitates were harvested and imaged using a µCT scanner. The intraosseous vascularity was incorporated into a 3-dimensional image. We measured the vascular pattern as well as the vessels' cross-sectional area, number, and distribution. An average capitate fracture line was calculated using clinical data from 22 patients with capitate fractures. The fracture line was projected on the representative capitate to assess its relation with the nutrient vessels' entry points. RESULTS: The capitate is a well-vascularized carpal supplied by dorsal and volar vascular systems that anastomose in 30% of cases. There was no predominance of one vascular system over the other. Most vessels enter the capitate at the distal half and supply the proximal pole in a retrograde fashion. In addition, most specimens (70%) also had at least one vessel entering the proximal pole through the volar capitate ligaments and supplying the proximal pole directly. The average fracture line had an oblique orientation, and 90% of the specimens had a blood vessel entering proximal to that line. CONCLUSIONS: This µCT vascular study further verifies that the capitate receives most of its vasculature in a retrograde fashion, but the study also shows that most capitates have vessels supplying the proximal pole directly. These findings might explain why most capitate waist fractures do not progress to proximal pole avascular necrosis. CLINICAL RELEVANCE: This study characterizes the microvasculature of the capitate and might shed light on processes involved in bone healing and the etiology of capitate avascular necrosis.

Metal-on-Metal Hip Replacement: MRI Signal Intensities of Different Body Tissues and Their Relations to Blood Metal Ion Levels.

BACKGROUND: Metal-on-metal total hip prostheses (MoM-THR) have been shown to produce hypersensitivity reactions and fluid collection (pseudotumor) by the hip as well as high blood metal ions levels (BMILs). OBJECTIVES: To evaluate the magnetic resonance imaging (MRI) signal-to-noise ratio (S/N) in selected body tissues around the hip of patients who underwent MoM hip replacement and to correlate to BMILs. METHODS: Sixty-one MRI hip examinations in 54 post-MoM-THR patients (18 males, 36 females, mean age 65 years) were retrospectively evaluated independently by two readers. The mean S/N ratio in a region of interest was calculated for periprosthetic pseudotumor collection (PPC), the bladder, fat, and muscle on axial T1w, FSE-T2w, and short tau inversion recovery (STIR) sequences on the same location. BMILs were retrieved from patient files. RESULTS: PPC was detected in 32 patients (52%) with an average volume of 82.48 mm3. BMIL did not correlate with the presence of PPCs but positively correlated with the PPC's volume. A trend for positive correlation was found between BMILs and S/N levels of STIR images for muscle and bladder as well as for PPC and cobalt levels. A trend for correlation was also seen between BMIL with PPC's T1 w S/N. CONCLUSIONS: Alteration of MRI S/N for different hip tissues showed a tendency for correlation with BMILs, possibly suggesting that metal deposition occurs in the PPC as well as in the surrounding tissues and bladder.

Ochrobactrum anthropi-Caused Osteomyelitis in the Foot Mimicking a Bone Tumor: Case Report and Review of the Literature.

Osteomyelitis due to Ochrobactrum anthropi, a new genus Ochrobacterum widely distributed in the environment and occasionally associated with human infection, has been described in only a few case reports. We present a report of an unusual case of osteomyelitis caused by O. anthropi that was identified 9 years after a nail puncture to the lateral cuneiform bone. The patient was an 18-year-old male with a painful foot lesion that had originally been misdiagnosed as an osteolytic tumor. He underwent surgery and 2 firm pieces of rubber measuring 7 and 10 mm were removed from the lower portion of the lateral cuneiform bone, which appeared to be affected by an infection. After surgical debridement, O. anthropi was isolated from the bone cultures. The patient was successfully treated with a 6-week course of oral ciprofloxacin and clindamycin. At 1 year after the corrected diagnosis and appropriate treatment, he was symptom free and had resumed regular activities and an athletic lifestyle.

Bilateral total hip replacement: periprosthetic pseudotumor collections are more prevalent in metal-on-metal implants compared to non-metal-on-metal ones.

BACKGROUND: Metal-on-metal (MoM) hip prostheses were shown to have high failure rates including the formation of periprosthetic cystic masses called periprosthetic pseudotumor collections (PPCs). PURPOSE: To compare MRI prevalence and size of PPCs in patients after bilateral total-hip-replacement (THR) in which at least one hip was replaced by a MoM prosthesis. MATERIAL AND METHODS: All sequential MRI examinations of patients with bilateral THR in which at least one is MoM (2010-2013) were retrospectively evaluated. MRIs were analyzed separately by two readers for the presence and size of PPCs. These were compared between MoM and non-MoM implants and between patients with unilateral or bilateral-MoM prostheses. Blood metal ion levels were also compared. RESULTS: Seventy hips of 35 patients (male:female ratio, 9:26; mean age, 64 years; age range, 35-82 years) were assessed. Sixteen patients (45%) underwent bilateral MoM-THRs and 19 (55%) had one MoM and the other non-MoM, yielding 51 MoM THRs and 19 non-MoM THRs. Twenty-eight PPCs were detected in 19 patients (54%): 26 in MoM THRs (51%) and two in non-MoM THRs (10.5%, P = 0.00009). The mean PPC volume in the MoM implants (107 mm(3)) was higher than that of the non-MoM implants (18 mm(3), P = 0.49). Cobalt/chromium blood levels were 78 µg/L/25 µg/L for bilateral MoM THRs and 21 µg/L/10 µg/L for unilateral MoM implants (P = 0.1 and 0.16, respectively). CONCLUSION: PPCs are more prevalent in MoM THRs compared to non-MoM THRs. Larger PPC volumes and higher blood metal ion levels were detected in patients with bilateral MoM THRs compared to unilateral MoM THRs (P > 0.05).

The results of two-stage revision TKA using Ceftazidime-Vancomycin-impregnated cement articulating spacers in Tsukayama Type II periprosthetic joint infections.

PURPOSE: This study examined the success and factors associated with failure, of using cement spacers impregnated with high-dose Ceftazidime and Vancomycin when performing two-stage revision for infected total knee arthroplasty (TKA). METHODS: A retrospective analysis was performed using a prospectively collected database of 82 patients (median age 68 years, range 39-87) with a confirmed deep TKA infection treated with a two-stage revision. All cement spacers were impregnated with high-dose Ceftazidime and Vancomycin. The rate of success was recorded-an association between failure of treatment, and patient factors, previous surgical treatment, and microbial characteristics was sought. RESULTS: The mean time to infection from index arthroplasty was 45 months (range 3-240). The initial two-stage revision was successful in 70/82 patients (85.4 %), who remained free of infection at average follow-up of 36.2 months (range 24-85). A second two-stage revision for infection was required in 12/82 patients (14.6 %), which was successful in 4/12 (33 %). A third two-stage revision was performed in three patients, all of whom had a polymicrobial infection of which only one patient had successful eradication of infection. Recurrent infection was correlated with irrigation and debridement with implant retention prior to initial two-stage revision (p < 0.01), polymicrobial infections (p = 0.035), and infections presenting <6 months after index surgery (p = 0.031). No correlation was seen with age, BMI, type of organism, diabetes mellitus, or Charlson Comorbidity Index. CONCLUSION: The findings of this study suggest that the combination of Ceftazidime and Vancomycin in cement spacers is as efficacious as other published single or combined antibiotic mixtures, which is clinically relevant to clinicians treating this difficult problem in the setting of patients with compromised renal function.

Capitate Fractures: A Review of 53 Patients.

PURPOSE: To describe the demographics, diagnosis, management, and outcomes of capitate fractures in the adult and pediatric population treated in our institution. METHODS: We performed a retrospective chart and radiographic review of 53 patients with capitate fractures treated in our institution between 2002 and 2015. Patients' demographic characteristics, mechanism of injury, management including surgery-related data, and outcomes, including complications, were recorded. A radiographic evaluation of the location and pattern of the fracture was performed. RESULTS: Capitate fractures were prevalent in young males and older females. Fracture location was variable with 9 different locations; in addition 80% of patients had an associated fracture in the wrist or hand. The most common fracture pattern was the transscaphoid, transcapitate perilunate dislocation. Most diagnoses were made with the aid of advanced imaging. Within this series, there was only 1 case (4%) of fracture nonunion and there were no cases of avascular necrosis of the proximal pole in limited follow-up. Isolated capitate fractures were significantly more common in children. In addition, children had better functional outcomes than adults. CONCLUSIONS: This series provides updated information on this rare injury. Nonunion of the capitate, which was previously described as the most common complication, was rare in this cohort. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Anchor suture fixation of distal pole fractures of patella: twenty seven cases and comparison to partial patellectomy.

PURPOSE: Partial patellectomy (PP) and reattachment of the patellar ligament with transosseous suturing is the mainstay of surgical treatment for distal pole patellar fractures. An anchor suturing (AS) technique has recently been reported as an alternative to PP in such fractures and allows for bone-to-bone interface and possibly superior fracture healing than bone-to-tendon interface with PP. We present our experience with AS and compare it to PP. METHODS: Between 2006 and 2011, 60 patients with distal pole patellar fracture underwent either AS (n = 27) or PP (n = 33). We retrospectively gathered their demographic data and information on fracture type, fixation technique, operation time, postoperative complications and knee range of motion. A telephone survey was performed to grade functional outcomes with standard questionnaires (the SF-12 for quality of life, the Kujala score for patellofemoral function and a visual analog scale [VAS] pain score). RESULTS: AS was equivalent to PP in terms of residual pain and functional outcomes (VAS: 2.45 vs. 2.26, p = 0.83 and Kujala score: 74.3 vs. 69, p = 0.351, respectively) as well as for knee range of motion. Complications included three cases of infection in each group, two cases of early hardware failure and one case of non-union in the AS group. Operation time was significantly shorter for AS compared to PP (68.5 vs. 79.1 min, p = 0.03). CONCLUSIONS: AS is non-inferior to PP for function and pain after distal pole patellar fractures and is superior to PP with regard to operative time. Common complications of this technique are hardware failure and infections. LEVEL OF EVIDENCE: Therapeutic Level III.

Predictors for nonunion, reoperation and infection after surgical fixation of patellar fracture.

INTRODUCTION: The most common major complications following surgical fixation of patellar fractures are infection, nonunion and reoperation. In this study, we sought to define the predisposing factors to the development of these complications. METHODS: Open reduction and internal fixation surgeries for patellar fractures that were performed in a single institution between 2006 and 2011 were retrospectively reviewed. Patients' demographic data (age, gender, comorbidities), injury and fracture data (associated injuries, type of fracture, open or closed fracture), surgical data (type of surgery and interval between fracture occurrence and surgery) and major postoperative complications (infection, nonunion, symptomatic hardware and revision surgery) were collected from the medical records and verified by a telephone survey. Correlation analysis identified the major variables influencing the development of these complications. RESULTS: The cohort of 188 patients had an average follow-up of 908 days. Thirteen (6.9 %) patients developed infection, 3 (1.6 %) had fracture nonunion and 42 (22.3 %) required a second operation. A history of cerebrovascular accident (CVA) correlated significantly with the development of infection (OR 6.18, CI 1.1-35.6, p = 0.041) and nonunion (OR 14.9, CI 1.2-188.1; p = 0.037). A history of diabetes significantly increased the risk of a second operation (OR 8.69, CI 95 % 1.8-41.9, p = 0.007). Open fracture did not increase the risk of any of these complications. CONCLUSIONS: A history of CVA and diabetes mellitus significantly increased the risk of complications following patellar fracture fixation. Patients with these comorbidities should be informed of their increased risk of these complications and be followed up more rigorously.