Equivalent revision rates and patient reported outcomes with routine use of a short (125mm) cemented stem for total hip arthroplasty compared to a standard length (150mm) cemented stem. A two surgeon series of 1335 patients.

BACKGROUND: Routine total hip arthroplasty (THA) using a short cemented stem as compared with a standard length cemented stem may have benefits in terms of stress distribution, bone preservation, stem subsidence and ease of revision surgery. Two senior arthroplasty surgeons transitioned their routine femoral implant from a standard 150 mm Exeter V40 cemented stem to a short 125 mm Exeter V40 cemented stem for all patients over the course of several years. We analysed revision rates, adjusted survival, and PROMS scores for patients who received a standard stem and a short stem in routine THA. METHODS: All THAs performed by the two surgeons between January 2011 and December 2021 were included. All procedures were performed using either a 150 mm or 125 mm Exeter V40 stem. Demographic data, acetabular implant type, and outcome data including implant survival, reason for revision, and post-operative Oxford Hip Scores were obtained from the New Zealand Joint Registry (NZJR), and detailed survival analyses were performed. Primary outcome was revision for any reason. Reason for revision, including femoral or acetabular failure, and time to revision were also recorded. RESULTS: 1335 THAs were included. 516 using the 150 mm stem and 819 using the 125 mm stem. There were 4055.5 and 3227.8 component years analysed in the standard stem and short stem groups respectively due to a longer mean follow up in the 150 mm group. Patient reported outcomes were comparable across all groups. Revision rates were comparable between the standard 150 mm stem (0.44 revisions/100 component years) and the short 125 mm stem (0.56 revisions/100 component years) with no statistically significant difference found (p = 0.240). CONCLUSION: Routine use of a short 125 mm stem had no statistically significant impact on revision rate or PROMS scores when compared to a standard 150 mm stem. There may be benefits to routine use of a short cemented femoral implant.

The incidence of symptomatic venous thromboembolism following orthopaedic surgery at Bay of Plenty District Health Board.

AIM: To investigate the incidence of symptomatic venous thromboembolism (VTE) after orthopaedic surgery. METHOD: We performed a retrospective cohort study investigating the incidence of symptomatic VTE within 90 days of orthopaedic surgery in the Bay of Plenty District Health Board (DHB). Risk factors and antithrombotic regimens were also reviewed. RESULTS: After 1,133 unilateral total hip joint replacements (THJRs), there were six VTEs (incidence 0.5%, 95% CI 0.2-1.1%), four deep vein thromboses (DVT) (0.4%, 0.1-0.9%) and three pulmonary emboli (PE) (0.3%, 0.1-0.8%). Following 898 unilateral total knee joint replacements (TKJRs), 18 patients developed VTEs (2.0%, 1.2-2.9%), five developed DVTs (0.6%, 0.2-1.3%) and 16 developed PEs (1.8%, 1.1-2.9%). There were five VTEs after 224 THJR revisions (2.2%, 1.0-5.1%), five VTEs after 110 TKJR revisions (4.5%, 2.0-10.2%) and 16 VTEs after 846 hip fracture surgeries (1.9%, 1.2-3.0%). VTE risk factors were ICU admission post operatively and having known coronary or cerebrovascular disease. Within 1 week of surgery, 38.5% (30/78) of VTEs were diagnosed and within 2 weeks 66.7% (52/78) were diagnosed. Aspirin was being taken by 44% (34/78) of VTE patients and 26% (19/78) were on more potent antithrombotics. CONCLUSION: VTE is a rare complication of orthopaedic surgery. The highest risk period is the initial 2 weeks after a procedure. VTE can develop despite pharmacological thromboprophylaxis.

Comparing modern uncemented, hybrid and cemented implant combinations in older patients undergoing primary total hip arthroplasty, a New Zealand Joint Registry study.

BACKGROUND: Multiple joint registries have reported better implant survival for patients aged > 75 years undergoing total hip arthroplasty (THA) with cemented implant combinations when compared to hybrid or uncemented implant combinations. However, there is considerable variation within these broad implant categories, and it has therefore been suggested that specific implant combinations should be compared. We analysed the most common contemporary uncemented (Corail/Pinnacle), hybrid (Exeter V40/Trident) and cemented (Exeter V40/Exeter X3) implant combinations in the New Zealand Joint Registry (NZJR) for patients aged > 75 years. METHODS: All THAs performed using the selected implants in the NZJR for patients aged > 75 years between 1999 and 2018 were included. Demographic data, implant type, and outcome data including implant survival, reason for revision, and post-operative Oxford Hip Scores were obtained from the NZJR, and detailed survival analyses were performed. Primary outcome was revision for any reason. Reason for revision, including femoral or acetabular failure, and time to revision were recorded. RESULTS: 5427 THAs were included. There were 1105 implantations in the uncemented implant combination group, 3040 in the hybrid implant combination group and 1282 in the cemented implant combination group. Patient reported outcomes were comparable across all groups. Revision rates were comparable between the cemented implant combination (0.31 revisions/100 component years) and the hybrid implant combination (0.40 revisions/100 component years) but were statistically significantly higher in the uncemented implant combination (0.80/100 component years). Femoral-sided revisions were significantly greater in the uncemented implant combination group. CONCLUSION: The cemented implant and hybrid implant combinations provide equivalent survival and functional outcomes in patients aged over 75 years. Caution is advised if considering use of the uncemented implant combination in this age group, predominantly due to a higher risk of femoral-sided revisions. The authors recommend comparison of individual implants rather than broad categories of implants.

Comparing uncemented, hybrid and cemented primary total hip arthroplasty in young patients, a New Zealand Joint Registry study.

BACKGROUND: Despite increasing use of uncemented implants in young patients undergoing total hip arthroplasty (THA), there is minimal evidence for specific implant combinations in this group. We analysed the most commonly used uncemented (Corail-Pinnacle), hybrid (Exeter-Trident/Tritanium), and fully cemented (Exeter) implant combinations in the New Zealand Joint Registry (NZJR) in patients aged under 40 and between 40 and 55 years. METHODS: All THAs recorded in the NZJR between 1999 and 2018 were included. The 40-55 and < 40 age groups were analysed separately. Demographic data, implant type, and outcome data including implant survival, reason for revision, and post-operative Oxford Hip Scores were obtained from the NZJR, and detailed survival analyses were performed. The primary outcome was revision for any reason. RESULTS: We identified 4152 THAs in the 40-55 group and 422 in the < 40 group. In the 40-55 group, revision rates and patient-reported outcome measure scores were comparable between the uncemented implant combination (0.70/100 component years) and the hybrid implant combination (0.62/100 component years), whereas the cemented implant combination exhibited a statistically significant higher revision rate (1.75/100 component years) (p < 0.001). In the < 40 group, revision rate for the hybrid implant combination (0.46/100 component years) was significantly lower than the uncemented implant combination (1.54/100 component years). CONCLUSION: The most commonly used hybrid and uncemented implant combinations provided equivalent survival and functional outcomes in patients aged 40-55 years. More research is required to guide implant selection in patients aged < 40 years. The authors suggest a transition away from comparing classes of implants (cemented, uncemented, hybrid) given the diverse product range within these categories.

Tranexamic Acid in Knee Surgery Study-A Multicentered, Randomized, Controlled Trial.

BACKGROUND: Postoperative anemia following elective arthroplasty can lead to prolonged hospital stay and delays in rehabilitation and is often poorly tolerated in patients with cardiovascular disease. Tranexamic acid (TXA) has been shown to reduce perioperative blood loss in total knee arthroplasty (TKA). However, questions over its optimal route of administration remain. METHODS: A double-blinded, placebo, multicentered, randomized, controlled trial investigating the efficacy of topical and systemic routes of a single intraoperative dose (1.5 g) of TXA was conducted. Patients undergoing primary, unilateral TKA were screened for eligibility. Eligible patients were consecutively enrolled from 5 New Zealand centers between July 2014 and November 2015. Three prospective groups running in parallel (topical TXA [tTXA], systemic TXA [sTXA], and placebo) were investigated for a primary outcome of estimated perioperative blood loss. An intention-to-treat analysis was used to compare outcomes between the study groups (P value <.05). RESULTS: One hundred and thirty-four patients across the 5 hospitals were recruited into the study. Estimated blood loss was equivalent in the 2 treatment groups, sTXA (749 mL [95% confidence interval, 637-860]) and tTXA (723 mL [620-826]). Compared to the placebo group (1090 mL [923-1257]), blood loss was significantly lower in both treatment groups (P = .001 and P = .0003, respectively). There were no significant differences in secondary outcomes, including rates of symptomatic deep vein thrombosis and pulmonary embolism (P = .759). CONCLUSION: In the setting of elective TKA, a single 1.5-g dose of tTXA given intraoperatively either systemically or topically effectively reduces blood loss without an increase in complications.

A Ruptured Digital Epidermal Inclusion Cyst: A Sinister Presentation.

Epidermal inclusion cysts are benign cutaneous lesions caused by dermal or subdermal implantation and proliferation of epidermal squamous epithelium as a result of trauma or surgery. They are typically located on the scalp, face, trunk, neck, or back; however they can be found anywhere on the body. Lesions are asymptomatic unless complicated by rupture, malignant transformation to squamous cell carcinoma, or infection at which point they can clinically appear as more sinister pathologies. We present the case of a 45-year-old laborer with a ruptured epidermal inclusion cyst, manifesting clinically and radiographically as a malignancy. Following MRI, definitive surgical management may appear to be a logical progression in management of the patient. This case however is a good example of why meticulously following surgical protocol when evaluating an unknown soft tissue mass is imperative. By following protocol, an alternate diagnosis was made and the patient has since gone on to a make a full recovery without life transforming surgery.

Are there differences between Maori and non-Maori patients undergoing primary total hip and knee arthroplasty surgery in New Zealand? A registry-based cohort study.

AIM: It has been well demonstrated that Maori have the poorest health status of any ethnic group in New Zealand. The aim of this study was to determine whether there are any differences between Maori and non-Maori patients in the severity of their arthritis preoperatively and in their postoperative functional outcomes following primary total hip and knee arthroplasty surgery. Secondary objectives were to compare general and mental health scores and to determine whether the intervention rate for Maori arthroplasty patients is appropriate. METHOD: We compared preoperative and postoperative (1 and 5 year) Oxford and WOMAC scores, general health (SF-12 PH) and mental health (SF-12 MH) scores in all public patients who underwent primary total hip and knee arthroplasty surgery in our region between 2005 and 2009. RESULTS: Maori patients are younger at the time of surgery, have higher ASA scores and worse preoperative function. They also have worse postoperative outcomes and smaller overall improvements following surgery when comparing their preoperative with postoperative scores. In terms of general health, Maori and non-Maori had similar SF-12 PH scores but worse SF-12 MH scores both pre- and postoperatively. CONCLUSION: Maori patients are younger, have worse general and mental health and worse preoperative function compared with non-Maori patients. Both absolute and differential scores show that Maori patients also have worse postoperative outcomes compared with non-Maori patients. These differences are likely clinically significant and ongoing education and effort is required in order to achieve earlier intervention rates and improve postoperative outcomes for Maori patients.

Failure strengths of concentric and eccentric implants for hamstring graft fixation.

The purpose of this study is to compare the initial failure strengths of various interference screw devices used for tibial fixation of hamstring grafts in anterior cruciate ligament reconstruction and the effect of concentric or eccentric screw position. Quadrupled tendon grafts were harvested from freshly killed sheep. The grafts were then prepared and fixed in the distal femur using various devices (Intrafix (DePuy Mitek Raynham, MA, USA), RCI screw (Smith and Nephew Acufex, Mansfield, MA, USA), Wedge screw (Stryker Endoscopy, San Jose, CA, USA) in concentric position and Wedge screw in eccentric position with an interlock pin). The load required to cause mechanical failure of each construct was measured. The Intrafix device had a significantly greater mean strength to failure than all the other implants (mean 941 +/- 280 N) (P = 0.015 to P < 0.0001). The wedge screw inserted concentrically (737 +/- 134 N) had significantly greater initial failure strength than the wedge eccentric with interlock pin (458 +/- 266 N) (P = 0.03) and the RCI screw (464 +/- 107 N) (P = 0.00036). In this sheep model the Intrafix device with sheath inserted concentrically had significantly greater initial failure strength than the other interference screws. Concentric positioning of the wedge interference screw gave significantly greater initial failure strength of a quadruple tendon graft than eccentric positioning. The use of the Intrafix device or concentric positioning of an interference screw should result in increased initial fixation strength of hamstring grafts. This may allow more vigorous early rehabilitation and may result in less late graft laxity after anterior cruciate ligament reconstruction.

Ultrasound measurements in the management of unstable hips treated with the pavlik harness: reliability and correlation with outcome.

The purposes of this study were to determine the interobserver and intraobserver reliability of ultrasound measurements in unstable neonatal hips treated with the Pavlik harness and to determine whether ultrasound measurements correlate with radiological outcome at 6 months. Sixty-four babies treated from birth with the Pavlik harness for neonatal hip instability were scanned at 2 and 6 weeks. The alpha and beta angles of Graf, the combined (H) angle of Hosny, and the femoral head coverage (FHC) were measured by 3 observers and remeasured by each observer on a minimum of 50 scans. From 248 scans, 792 sets of measurements were made. Hips were categorized as normal, abnormal, or borderline for each parameter; and interobserver and intraobserver repeatability coefficients and Kappa values were calculated. The alpha angle had the smallest interobserver range (17 degrees), the H angle range was 21 degrees, and the beta angle 28 degrees. Kappa values were best for the FHC and beta angle (0.66-0.8). The mean acetabular index (AI) of all hips at 6 months was 26 degrees (SD, 4.9). The AI was 30 degrees or greater in 24 hips (18 babies) despite prolonged splintage in 9 hips (6 babies). A stepwise linear regression analysis showed that the FHC at 6 weeks was predictive of AI at 6 months (regression coefficient -0.27; 95% confidence interval -0.42 to -0.12; P<0.001). We recommend the FHC as being reproducible, useful, and predictive of outcome in neonatal hips treated for instability.

The diagnosis and management of neonatal hip instability: results of a clinical and targeted ultrasound screening program.

This article reports the results of a neonatal hip screening program comprising clinical screening and targeted ultrasound performed by orthopaedic surgeons. Over 7 years, from 1995 to 2001, there were 15,397 live births in the authors' region. Seven hundred thirty-three babies (4.8% of births) were referred for hip ultrasound: 80% for risk factors and 20% for instability. Eighty-three babies (5.4/1,000) were splinted in a Pavlik harness. Three of these subsequently required surgery (1.9/1,000). Ten patients (0.65/1000) presented with hip dislocation after 12 weeks of age, nine of whom required open or closed reduction (0.56/1,000). From 1978 to 1985, when neonatal pediatricians clinically screened all babies, 18 babies presented late from 13,707 births (1.3/1000). Since the introduction of orthopaedic screening and targeted ultrasound, there has been a significant reduction in late diagnosis in the authors' institution.