AI and the nature of disagreement.

Litigation is a creature of disagreement. Our essay explores the potential of artificial intelligence (AI) to help reduce legal disagreements. In any litigation, parties disagree over the facts, the law, or how the law applies to the facts. The source of the parties' disagreements matters. It may determine the extent to which AI can help resolve their disputes. AI is helpful in clarifying the parties' misunderstanding over how well-defined questions of law apply to their facts. But AI may be less helpful when parties disagree on questions of fact where the prevailing facts dictate the legal outcome. The private nature of information underlying these factual disagreements typically fall outside the strengths of AI's computational leverage over publicly available data. A further complication: parties may disagree about which rule should govern the dispute, which can arise irrespective of whether they agree or disagree over questions of facts. Accordingly, while AI can provide clarity over legal precedent, it often may be insufficient to provide clarity over legal disputes. This article is part of the theme issue 'A complexity science approach to law and governance'.

Growth of the New Thumb Metacarpal After Pollicization for Thumb Hypoplasia.

PURPOSE: To investigate the radiographic length and width of the new thumb metacarpal in relation to the middle finger proximal phalanx; to assess the incidence of premature physeal closure of the new metacarpal; and to consider whether there is a relationship between growth characteristics and the presence of union or nonunion of the new trapezium to the retained index finger metacarpal base. METHODS: Forty pollicizations were assessed with preoperative or immediate postoperative radiographs and follow-up radiographs to establish the growth characteristics of the new thumb metacarpal. Functional outcomes comprising grip strength, pinch strength, and range of motion were correlated with radiological findings of presence or absence of open physes and presence or absence of union of the new trapezium to the metacarpal base. RESULTS: The new thumb metacarpal physis was open in 28 pollicizations and closed in 12. In the latter group, all physes of the hand had closed indicating skeletal maturity. The length and width indices of the new thumb metacarpal in relation to the middle finger proximal phalanx were equivalent to or greater than the perioperative growth indices. There was a reduced postoperative length ratio in those patients with nonunion of the new trapezium to the base of the metacarpal. There was no change in strength and range of motion parameters with growth other than that related to normal improvement with age. CONCLUSIONS: We are unable to demonstrate premature physeal closure following routine pollicization. The growth of the metacarpal continues in a normal manner to skeletal maturity. A failure of union of the new trapezium to the metacarpal base may compromise growth. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Stability of the Basal Joints of the New Thumb After Pollicization for Thumb Hypoplasia.

PURPOSE: To investigate the presence or absence of union of the new trapezium to the retained metacarpal base after pollicization and to relate this to stability of the new trapezium and the new carpometacarpal joint. METHODS: Thirty-six patients (46 pollicizations) were assessed at clinical review. Mean time from surgery to review was 96 months (range, 9-260 mo). Clinical assessment measured range of motion (ROM) at the carpometacarpal joint, stability of the carpometacarpal joint, and extrinsic and intrinsic strength of both hands. Radiological review evaluated 3 parameters: bony union between the new trapezium and retained metacarpal base, stability of the new trapezium in relationship to the metacarpal base, and carpometacarpal joint stability. RESULTS: There was radiographic nonunion between the new trapezium and the retained metacarpal base in 8 (1 treated) of 46 pollicizations. Relative risk of instability of the new trapezium was 39 times more likely if nonunion was present. Nine pollicizations were unstable at the carpometacarpal joint, 8 in those with union and 1 with nonunion. Relative risk of instability was 1.4 times more likely for those with union. For patients with nonunion, ROM and grip strength variables were reduced but only grip strength reached statistical significance. In patients with carpometacarpal joint instability, ROM and grip strength variables were reduced but none of the variables reached statistical significance. CONCLUSIONS: This study suggests that when the surgeon is attempting to obtain union of the new trapezium to the retained metacarpal base, failure to do so results in a poorer thumb with a significantly increased risk of trapezial instability and decreased grip strength. There is a mildly increased risk of carpometacarpal joint instability with union, but significantly poorer function as a consequence of this has not been demonstrated. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Is ORIF superior to nonoperative treatment in isolated displaced partial articular fractures of the radial head?

BACKGROUND: While good results have been reported with both nonoperative and operative treatment of isolated displaced partial radial head fractures, there remains considerable disagreement about the role of surgery in the management of these injuries. QUESTIONS/PURPOSES: We (1) compared isolated displaced partial articular radial head fractures treated nonoperatively with open reduction internal fixation (ORIF) in terms of validated outcomes scores, ROM, and strength; (2) assessed whether there were any predictor variables for outcomes; and (3) compared complications between groups. METHODS: We retrospectively compared patients with isolated partial articular radial head fractures displaced greater than 2 mm but less than 5 mm who received either nonoperative treatment (30 patients) or ORIF (30 patients). We reviewed the nonoperative and ORIF groups at a mean of 3 and 4.5 years, respectively. The nonoperative and ORIF groups were similar except for age (51 ± 17 years versus 39 ± 10 years, respectively) and fracture displacement (2.3 ± 0.3 mm versus 2.8 ± 0.6 mm, respectively). As there were no definitive guidelines on which treatment represented best management, treatment type was decided by the attending surgeon in conjunction with the patient on a case-by-case basis. Patients were evaluated using the Patient-rated Elbow Evaluation (PREE) (primary outcome measure), Mayo Elbow Performance Score (MEPS), QuickDASH, SF-12, clinical examination, and radiographic evaluation (14 and 28 in the nonoperative and ORIF groups, respectively). Elbow ROM was assessed with a goniometer and hand grip strength with calibrated strength testing. We assessed possible predictive variables (age, displacement, energy of injury) for clinical outcome scores and recorded complications. RESULTS: PREE scores were not different between groups, but the MEPS favored the nonoperative group (93 versus 86; p = 0.012). ROM and grip strength were similar between groups. Younger age was associated with worse outcome, but displacement and energy were not. More complications occurred in the ORIF group (eight cases of mild heterotopic ossification, two cases of hardware failure) than in the nonoperative group (one case of mild heterotopic ossification, one case of complex regional pain syndrome). CONCLUSIONS: No clinical benefit with ORIF could be found compared to nonoperative management of isolated partial articular radial head fractures with displacement of greater than 2 mm but less than 5 mm at short-term followup. A well-designed randomized trial and followup at longer term are required to provide better information about how to treat these common fractures. LEVEL OF EVIDENCE: Level III, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Radial head fractures.

Fractures of the radial head are the most common fractures in the elbow, and they frequently have associated ligamentous, cartilaginous, or other bony injuries. Clinical assessment and radiological investigation allow for accurate diagnosis and the formulation of a management plan. Undisplaced or minimally displaced fractures with no rotational block to motion can be treated nonoperatively with excellent results expected. The minimum amount of displacement in a partial articular radial head fracture required for open reduction and internal fixation to provide a superior outcome to nonoperative management is still unknown. Medium-term data suggest that patients with comminuted radial head fractures do well with radial head replacement.

Single versus triple injection ultrasound-guided infraclavicular block: confirmation of the effectiveness of the single injection technique.

BACKGROUND: The optimal site for local anesthetic placement during ultrasound-guided infraclavicular block remains controversial. METHODS: Patients were randomized to receive lidocaine 2% 30 mL as a single injection posterior to the axillary artery (n = 51) or a triple injection ideally adjacent to each brachial plexus cord (n = 49). Pinprick sensory and motor block (3 = no block, 0 = complete block) were assessed to 20 minutes in the 4 distal nerve territories. RESULTS: The single injection group was not significantly inferior (single versus triple injection median [interquartile range] 20-minute aggregate block score: 5 [2-9] vs 7 [3.5-11]) but also demonstrated superiority (2-tailed test, P = 0.043). The single injection technique was associated with a small reduction in procedural time. CONCLUSIONS: The optimal site for local anesthetic placement during ultrasound-guided infraclavicular block is a single point injection posterior to the axillary artery.

Cystic eccrine spiradenoma of the finger mimicking a ganglion.

SUMMARY: We report a rare case of cystic eccrine spiradenoma in the finger. A 46-year-old man presented with a cystic mass in his left index finger. Clinical assessment along with the investigation pointed toward a diagnosis of a ganglion. However, excisional biopsy of the mass revealed histopathological findings of cystic eccrine spiradenoma. Very few cases of eccrine spiradenoma have been reported in the hand and none of them were cystic in consistency. We believe that this case will draw the surgeon's attention to the possibility of unusual differential diagnoses in the evaluation and treatment of cystic lumps in the hand.

Management of distal radius fractures from the North American perspective.

In North America, the rate of nonoperative management of displaced distal radius fractures has declined as the rate of internal fixation has increased. Volar locking plate fixation has increased in popularity despite a lack of supportive level 1 evidence. Issues of cost-effectiveness are relevant because there is no best-practice treatment at this stage. Clinicians should be aware of the goals of treatment and challenges, particularly in managing elderly patients with distal radius fractures. Large, randomized controlled trials or meta-analyses may provide answers about when operative intervention is favored over nonoperative management and which operative intervention provides the best outcomes.