Functional alignment achieves a more balanced total knee arthroplasty than either mechanical alignment or kinematic alignment prior to soft tissue releases.

PURPOSE: Total knee arthroplasty with functional alignment uses pre-resection balancing to determine component position within the soft tissue envelope to achieve balance and restoration of native joint obliquity. The purpose of this study was to assess the balance achievable with a mechanical axis alignment and kinematic axis alignment plan, and the subsequent balance achievable after adjustment of the component position to functional alignment. METHODS: A prospective cohort of 300 knees undergoing cruciate retaining total knee arthroplasty were included in this study. Of these, 130 were initially planned with mechanical alignment (MA) and 170 with kinematic alignment (KA). Maximal stressed virtual gaps were collected using an optical tracking software system. The gaps were measured medially and laterally in flexion and extension. Following assessment of balance, implant position was adjusted to balance the soft tissues in functional alignment (FA) and the maximal gaps reassessed. Gaps were considered to be balanced when within 2 mm of equality. Incidence of balance within each cohort was compared to independent samples proportions test. RESULTS: Functional alignment obtained significantly better balance in extension, medially and overall than both MA and KA alignment without soft tissue release (p < 0.001). Overall balance was observed in 97% of FA knees, 73% of KA knees and in 55% of MA knees. The difference between KA and MA was also significant (p = 0.002). Whilst there was no difference observed in balanced achieved or limb alignment when FA was planned with either MA or KA, the joint line obliquity was maintained with an initial KA plan. CONCLUSION: Functional alignment more consistently achieves a balanced total knee arthroplasty than either mechanical alignment or kinematic alignment prior to undertaking soft tissue release. Utilising an individualised KA plan allows FA to best achieve the stated goals of maintaining joint line plane and obliquity. LEVEL OF EVIDENCE: Level III: retrospective cohort study.

Maintaining Joint Line Obliquity Optimizes Outcomes of Functional Alignment in Total Knee Arthroplasty in Patients With Constitutionally Varus Knees.

BACKGROUND: Functional alignment (FA) strives to balance the knee soft-tissue envelope during total knee arthroplasty (TKA) using implant alignment adjustments rather than soft-tissue releases. There is a debate on how best to achieve FA. We compared minimum two-year outcomes between FA with a mechanical alignment plan [FA(m)] and FA with a kinematic alignment plan [FA(k)]. The null hypothesis was that there would be no difference in outcomes between FA(m) and FA(k). METHODS: Prospective data was collected from 300 consecutive robotic-assisted FA TKAs [135 FA(m) and 165 FA(k)]. Patient reported outcomes were obtained preoperatively and 2 years postoperatively. The coronal plane alignment of the knee classification was used to classify knee alignment phenotypes. RESULTS: Overall limb alignment was equivalent between groups. Final implant alignment was different between FA(m) and FA(k) groups, with FA(k) TKAs having higher tibial varus (P < .01), higher femoral valgus (P < .01), and higher joint line obliquity (P < .01). Patients reported higher Forgotten Joint Score-12 scores with FA(k) TKAs (79.4 versus 71.6, P = .018) and greater range of motion (125 versus 121°; P = .003). Patients who had constitutional varus reported the greatest improvement with FA(k) technique (Forgotten Joint Score at minimum 2 years of 89 versus 65; P < .001). CONCLUSION: Utilizing an individualized alignment plan [FA(k)] led to a final implant position with greater joint line obliquity, yet the same overall limb alignment. This was associated with improved outcomes at 2 years post-TKA in patients who had constitutional varus. Three-dimensional component position and joint line obliquity affect the outcomes following TKA independently of coronal limb alignment.

Unrecognised entrapment of a herniated bladder at the pubic symphysis following reduction and external fixation of an unstable pelvic fracture.

Bladder injury is frequently associated with complex pelvic fractures with men being the predominant population to sustain such injuries. Entrapment of the bladder through the site of pelvic fracture is a rare clinical entity. We report a case of an entrapped bladder post closed reduction and external fixation of an unstable anteroposterior compression type 3 (APC-3) fracture. This report highlights the diagnostic difficulty with identifying an entrapped bladder and the patient's functional outcome after 1 year of follow-up.

Short-Term Benefits of Robotic Assisted Total Knee Arthroplasty Over Computer Navigated Total Knee Arthroplasty Are Not Sustained With No Difference in Postoperative Patient-Reported Outcome Measures.

Background: The purpose of this study was to compare early clinical and patient-reported outcomes between robotic assisted (RA) and computer navigation (CN) total knee arthroplasty (TKA). Methods: One hundred and fifty patients were enrolled in this prospective, single-surgeon, cohort study, with 75 patients each receiving CN-TKA or RA-TKA in a consecutive series. There were no differences in patient age (P = .34) or body mass index (P = .09), but a higher proportion of males underwent RA-TKA (P = .03). We recorded hospital knee pain, analgesic usage, length of hospital stay, range of motion, and patient-reported outcome measures postoperatively for both patient cohorts. Results: Hospital length of stay was shorter for the RA-TKA patients (P < .001). RA-TKA patients showed improved range of motion (P < .001) and decreased pain scores (P = .006) on day 1. Subsequent days showed no significant differences. Narcotic usage was lower for the RA-TKA group on day 2 postoperatively (P = .03) and onwards. Total morphine equivalent dose was also significantly lower for the RA-TKA than for the CN-TKA group (P < .001). There was no difference in Forgotten Joint Score (P = .24) or Oxford Knee Score (P = .51) between groups at 2 years postoperatively. Conclusion: The use of RA-TKA demonstrated reduced postoperative analgesia usage and length of stay. There were no differences seen between CN-TKA and RA-TKA with respect to clinical outcomes at 2 years after surgery.

A prospective randomised control trial comparing functional with mechanical axis alignment in total knee arthroplasty: study protocol for an investigator initiated trial.

BACKGROUND: A drive to improve functional outcomes for patients undergoing total knee arthroplasty (TKA) has led to alternative alignment being used. Functional alignment (FA) uses intraoperative soft tissue tension to determine the optimal position of the prosthesis within the patient's soft tissue envelope. Angular limits for bone resections are followed to prevent long-term prosthesis failure. This study will use the aid of robotic assistance to plan and implement the final prosthesis position. This method has yet to be compared to the traditional mechanically aligned (MA) knee in a randomised trial. METHODS: A blinded randomised control trial with 100 patients will be undertaken via Perth Hip and Knee Clinic. Fifty patients will undergo a MA TKA and fifty will undergo a FA TKA. Both alignment techniques will be balanced via computer-assisted navigation to assess prosthetic gaps, being achieved via the initial bony resection and further soft tissue releases as required to achieve satisfactory balance. The primary outcome will be the Forgotten Joint Score (FJS) 2 years after surgery, with secondary outcomes being other patient-reported outcome measures, clinical functional assessment, radiographic position and complications. Other data that will be collected will be patient demography (sex, age, level of activity) and medical information (grade of knee injury, any other relevant medical information). The linear statistical model will be fitted to the response (FJS), including all the other variables as covariates. DISCUSSION: Many surgeons are utilising alternative alignment techniques with a goal of achieving better functional outcomes for their patients. Currently, MA TKA remains the gold standard with good outcomes and excellent longevity. There is no published RCTs comparing FA to MA yet and only two registered studies are planned or currently in progress. This study utilises a FA technique which differs from the two studies. This study will help determine if FA TKA has superior functional results for patients. TRIAL REGISTRATION: This trial has been registered with the Australian New Zealand Clinical Trials Registry (ANZCTR) http://www.anzctr.org.au : U1111-1257-2291, registered 25th Jan 2021. It is also listed on www.clinicaltrials.gov : NCT04748510.

The use of anterior subcutaneous internal fixation (INFIX) for treatment of pelvic ring injuries in major trauma patients, complications and outcomes.

PURPOSE: Pelvic anterior internal fixators (INFIX) are a relatively new alternative in the treatment of unstable pelvic fractures. The authors wanted to review the use of complications and outcomes of this method of pelvic fixation at our institution. METHOD: Patients over the age of 18 who had an INFIX used in treatment of their pelvic ring injury were identified. Patient demographics, fracture type, injury severity score, morbidity, complications and time until removal were recorded. All available patients were followed up following the removal of the INFIX and completed an Iowa Pelvic Score (IPS) at this time. RESULTS AND DISCUSSION: 24 patients (19 male) with a mean age of 38.5 (range 18-71) met the inclusion criteria with an average injury severity score of 29.8 (10-66). The most common complication following insertion was a lateral femoral cutaneous nerve (LFCN) injury, which occurred in 11 patients (bilaterally in two), 6 patients (25%) had ongoing numbness 6 months post removal. Two patients had an infection, one of which prompted the removal of the INFIX. One INFIX was removed for implant failure. All other removals were planned electively. Heterotopic ossification was noted to have occurred in five cases. The mean IPS following removal of the INFIX was 79.2 (52-100). INFIX is a safe and successful treatment for unstable pelvic ring injuries. Overall, patients tolerate the INFIX well with good outcome scores. The main concern being the high rate of LFCN injuries, although many resolved after removal of the INFIX.

Arthroscopic reduction and percutaneous fixation of selected calcaneus fractures: surgical technique and early results.

OBJECTIVES: To highlight a technique combining fluoroscopy and arthroscopy to aid percutaneous reduction and internal fixation of selected displaced intra-articular calcaneal fractures, assess outcome scores, and compare this method with other previously reported percutaneous methods. DESIGN: Retrospective review of all patients treated by this technique between June 2009 and June 2012. SETTING: A tertiary care center located in Brisbane, Queensland, Australia. PATIENTS: Thirteen consecutive patients were treated by this method during this period. All patients had a minimum of 13 months follow-up and were available for radiological checks and assessment of complications; functional outcome scores were available for 9 patients. INTERVENTION: The patient was placed in a lateral decubitus position. Reduction was achieved with the aid of both intraoperative fluoroscopy and subtalar arthroscopy and held with cannulated screws in orthogonal planes. The patient was mobilized non-weight bearing for 10 weeks. MAIN OUTCOME MEASUREMENT: Outcomes measured were improvement in Bohler angle, postoperative complications, and 3 functional outcome scores (American Orthopaedic Foot and Ankle Society ankle-hindfoot score, Foot Function Index, and Calcaneal Fracture Scoring System). RESULTS: Mean postoperative improvement in Bohler angle was 18.3 degrees, with subsidence of 1.7 degrees. Functional outcome scores compared favorably with the prior literature. Based on available postoperative computed tomography scans (8/13), maximal residual articular incongruity measured 2 mm or less in 87.5% of our cases. CONCLUSIONS: Early results indicate that this technique, when combined with careful patient selection, offers a valid therapeutic option for the treatment of a distinct subset of displaced intra-articular calcaneal fractures, with diminished risk of wound complications. Large, prospective multicenter studies will be necessary to better evaluate the potential benefits of this technique. LEVEL OF EVIDENCE: Level IV Therapeutic. See Instructions for Authors for a complete description of levels of evidence.