Micromonas micros: A rare anaerobic cause of late implant failure following spinal surgery.

Context: Delayed, postoperative, spine infections are rare, most commonly occurring secondary to fastidious, less virulent pathogens. The etiology may involve a distant infectious focus, not related to the index operation. Patients may present months, or even years postoperatively with pain related to mechanical implant failure, often without additional signs of systemic infection.Findings: We present the case of a 59-year-old male who developed rapid disk degeneration and implant failure seven months following instrumented lumbar fusion surgery. The causal organism was found to be Micromonas micros, an anaerobic bacterium typically located in the oral cavity and associated with periodontal disease. The patient was found to have extensive oral caries, which were presumed to have occurred secondary to poor oral hygiene and his use of fentanyl lozenges for chronic back pain. The patient was treated with revision staged spinal surgery and long-term intravenous antibiotics.Conclusion/clinical relevance: This case highlights an unusual etiology of delayed postoperative spinal implant failure and provides evidence for periodontal disease as a source of hematogenous seeding in postoperative spinal infections. The orthopaedist should also be aware of the potential relationship between poor oral hygiene and the use of high sugar content fentanyl lozenges in treating chronic back pain in these patients.

A Machine Learning Algorithm to Predict the Probability of (Occult) Posterior Malleolar Fractures Associated With Tibial Shaft Fractures to Guide "Malleolus First" Fixation.

OBJECTIVES: To develop an accurate machine learning (ML) predictive model incorporating patient, fracture, and trauma characteristics to identify individual patients at risk of an (occult) PMF. METHODS: Databases of 2 studies including patients with TSFs from 2 Level 1 trauma centers were combined for analysis. Using ten-fold cross-validation, 4 supervised ML algorithms were trained in recognizing patterns associated with PMFs: (1) Bayes point machine; (2) support vector machine; (3) neural network; and (4) boosted decision tree. Performance of each ML algorithm was evaluated and compared based on (1) C-statistic; (2) calibration slope and intercept; and (3) Brier score. The best-performing ML algorithm was incorporated into an online open-access prediction tool. RESULTS: Total data set included 263 patients, of which 28% had a PMF. Training of the Bayes point machine resulted in the best-performing prediction model reflected by good C-statistic, calibration slope, calibration intercept, and Brier score of 0.89, 1.02, -0.06, and 0.106, respectively. This prediction model was deployed as an open-access online prediction tool. CONCLUSION: A ML-based prediction model accurately predicted the probability of a (occult) PMF in patients with a TSF based on patient- and fracture-specific characteristics. This prediction model can guide surgeons in their diagnostic workup and preoperative planning. Further research is required to externally validate the model before implementation in clinical practice. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

The Incidence of Posterior Malleolar Involvement in Distal Spiral Tibia Fractures: Is it Higher than We Think?

OBJECTIVES: To investigate the incidence of concomitant posterior malleolar fractures (PMFs) in operative, distal-third, spiral tibia fractures. DESIGN: Prospective protocol with retrospective review of data. SETTING: Single, Level 1 trauma center. PATIENTS/PARTICIPANTS: One hundred ninety-three consecutive, skeletally mature patients with operatively treated fractures of the distal-third, tibial shaft and metaphysis. Pilon fractures were excluded. INTERVENTION: Computed tomography (CT) scans were obtained in all distal-third, spiral fractures of the tibia to determine fracture morphology and presence of a PMF. MAIN OUTCOME MEASUREMENTS: The incidence of concurrent PMFs in operative spiral fractures of the distal tibia. RESULTS: Twenty-six distal-third, spiral fractures were identified with an ipsilateral PMF diagnosed in 92.3% of cases (24 cases). PMFs were over 25 times more likely to occur in distal-third, spiral fractures when compared with other distal-third fracture patterns (relative risk = 25.7, 95% confidence interval, 11.6-56.8). PMFs were treated with supplemental fixation in 23/24 (95.8%) cases. CONCLUSIONS: There is a high incidence of concomitant, ipsilateral fractures of the posterior malleolus in patients presenting with operative distal-third, spiral fractures of the tibia. A preoperative ankle computed tomography should be strongly considered in all cases with this specific fracture morphology. LEVEL OF EVIDENCE: Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Reliability and Clinical Utility of the CARDS Classification for Degenerative Spondylolisthesis.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: The objective of this study is to determine the reliability and clinical utility of the of the proposed CARDS classification for degenerative spondylolisthesis. BACKGROUND: The Clinical and Radiographic Degenerative Spondylolisthesis (CARDS) classification system was recently proposed as an alternative to the Meyerding system for classifying degenerative spondylolisthesis (DS). Unlike Meyerding, CARDS considers other relevant radiographic findings such as disk space collapse and segmental kyphosis to stratify DS into 4 radiographically discreet types. Currently, no studies have been conducted to assess the clinical utility of the CARDS system. METHODS: A total of 78 consecutive surgical patients with L4-L5 DS were rated as CARDS types A through D and Fleiss' κ for interobserver agreement was calculated. Then, demographics as well as preoperative and postoperative outcome scores (ODI, SF-12 mental and physical, VAS) were collected. The Kruskal-Wallis test was used to detect significant differences amongst CARDS types. An unpaired t test was used to compare individual CARDS types with all other subtypes combined. RESULTS: Grading showed: 4 type A, 19 type B, 45 type C, and 8 type D (k=0.63). There was a statistically significant difference in preoperative back pain (P=0.046) between groups. CARDS type D had the highest mean back pain scores (8.8) of all subtypes which was significantly higher than mean back pain for all other subtypes combined (P=0.016). CARDS D showed the largest degree of improvement in all outcome measures. There was a trend towards an increased improvement in ODI (P=0.074) and SF-12 MCS (P=0.095) in the CARDS D subtype relative to the rest of the cohort. CONCLUSIONS: The CARDS classification system represents a reliable method for classifying cases of DS. Our results indicate that kyphotic segmental alignment (CARDS D) may be a less common, yet clinically distinct subset of DS characterized by worse preoperative back pain. CARDS type D cases may also show a greater degree of improvement in multiple outcome measures following surgical intervention.

Zone II Flexor Tendon Repairs in the United States: Trends in Current Management.

PURPOSE: The repair of zone II flexor tendon injuries is an evolving topic in hand surgery with current literature suggesting the use of a 4-strand repair; 3-0 or 4-0 braided, nonabsorbable sutures; and an epitendinous repair. It was hypothesized that variability would exist within the hand surgeon community in treatment of zone II flexor tendon repairs in surgical material used, surgical technique, and postoperative rehabilitation protocol. METHODS: An online single-answer multiple-choice survey was distributed to the American Society for Surgery of the Hand members' database. Surgeons were asked questions about demographics, surgical technique, suture type, common complications, postoperative management, and the factor that plays the largest role in guiding their surgical preferences. Responses were compared with current medical evidence. RESULTS: A total of 410 individuals responded to the survey. In regards to technique, the majority of surgeons reported using a 4-strand repair; with 3-0 or 4-0 core braided, nonabsorbable sutures; and performing an epitendinous repair. Only 20% of surgeons surveyed reported ever using wide-awake local anesthesia, no tourniquet and postoperative protocols were split between early active and early passive rehabilitation. Senior surgeons (≥ 15 years in practice) were more likely than their colleagues to use a 2-strand repair and a passive rehabilitation protocol. CONCLUSIONS: This study demonstrates that the majority of respondents are performing zone II flexor tendon repairs in accordance with the best currently available evidence, although there is variability with respect to suture material, surgical technique, and rehabilitation protocols. CLINICAL RELEVANCE: There is still a need for high-quality studies on surgical technique and rehabilitation protocols.

Successful surgical treatment of an intraneural ganglion of the common peroneal nerve.

Intraneural ganglion cysts of peripheral nerves occurring within the epineural sheath are rare, and their mechanism of formation and treatment options are debated. We present a case of a 41-year-old man who presented with a complaint of lateral-sided left knee pain with numbness on the lateral side of the foot who was diagnosed with an intraneural ganglion of the common peroneal nerve (CPN). He was treated initially with common peroneal epineural decompression only to have symptoms recur 6 weeks postoperatively. The patient was subsequently treated utilizing the suggestions of the "unified articular theory," which proposes a small recurrent articular branch of the CPN as the source of cyst fluid. This branch was surgically detached, leading to complete alleviation of his symptoms. When the patient was reevaluated 2 years postoperatively, his preoperative symptoms had resolved, and a follow-up magnetic resonance image showed resolution of the enlargement of the CPN.