Aims

Due to the recent rapid expansion of scooter sharing companies, there has been a dramatic increase in the number of electric scooter (e-scooter) injuries. Our purpose was to conduct a systematic review to characterize the demographic characteristics, most common injuries, and management of patients injured from electric scooters.

Introduction

Close to 30% of the surgical causes of readmission within 90 days post-total knee arthroplasty (TKA) and nearly half of those occurring in the first 2 years are caused by instability, arthrofibrosis, and malalignment, all of which may be addressed by improving knee balance. Furthermore, the recently launched Comprehensive Care for Joint Replacement (CJR) initiative mandates that any increase in post-acute care costs through 90-days post-discharge will come directly from the bundle payment paid to providers. Post-discharge costs, including the cost of readmissions for complications are one of the largest drivers of the 90-day cost of care. It is hypothesized that balanced knees post-TKA will lower the true provider costs within the 90-day bundle.

Soft tissue balance and alignment have long been known to play an essential role in the long-term success of primary total knee arthroplasty (TKA). Until recently balance was confirmed based on intra-operative feel and experience. In this study we analyzed short-term outcomes of cruciate retaining TKA (CR-TKA) performed with a smart tibial trial device (STT), which provides real-time, intra-operative compartmental load and rotational congruency readings, to a comparable cohort of patients receiving conventional TKA where the same surgeon balanced the compartments based on feel and experience.

Seventy patients received CR-TKA with STT and were matched to one-hundred and eighty non-STT consecutive controls using the same anesthesia, surgical approach, and post-operative rehabilitation and pain management protocol. Both groups were evaluated preoperatively and then post-operatively at three months and one year using Short Form 12 (SF12) and the Western Ontario and McMaster University Osteoarthritis Index (WOMAC) questionnaires. T-tests were used to compare average scores within each cohort, as well as between the two cohorts, for each time interval.

The average age and BMI for the STT cohort were 70.9 ± 9.2 years and 29.8 ± 6.1 kg/m². Operation length was seen to be 12.0 minutes greater for the STT cohort compared to the conventional cohort (p = 0.0012). The average difference in pressure between medial and lateral compartments was 8.30, 11.49, and 8.65 lbs at 10°, 45°, and 90° respectively. Only 10 cases had a difference greater than 15 lbs between compartments. At 3 months, the STT cohort had significantly higher average function scores on the WOMAC (p=0.046) and higher change from baseline pain scores on the WOMAC (p=0.0016). When scores were stratified into the top 50% and the bottom 50% and the coronal balance was compared, SF12 pain scores and WOMAC function scores at 1 year in the top 50% had greater coronal balance indicated by pressure differences ≤ 15 lbs (p<0.002)

Given the results of this case-control study, we conclude that STT can indeed help the surgeon balance compartmental loads and femoral-tibial rotational congruency and lead to improved short-term physical and functional outcomes in primary CR-TKA.

Traditional medial soft tissue release for balancing of the varus knee in total knee arthroplasty can lead to an inconsistent reduction in medial tension. The purpose of this study is to establish whether sequential needle puncturing of the medial collateral ligament (MCL) can be a safe and predictable method for medial release.

Total knee prostheses were implanted in 14 cadaveric specimens by a single surgeon. Medial tension was measured in flexion and extension by a pressure sensor with implants in place, and calipers after removal of implants and gap distraction under constant tension. Measurements were performed after each of 5 sets of 5 punctures of the MCL with an 18-gauge needle and following 5 transverse perforations with an 11-blade. A consistent valgus force was applied after each set of MCL punctures with a pneumatic cylinder. Pearson's correlation was used to compare pressure sensor measurement with gap distance measurement under tension. The pressure as detected by the sensor after each set of 5 punctures was analyzed by a repeated measures two-way ANOVA and a Tukey multiple comparisons test to determine a significant decreases between puncture sets.

The pressure sensor device correlated more closely with systematic tissue release (r=0.59 for % change from baseline) than did measurements of gap increase under tension (r= −0.22). All knees had ≤5mm of medial opening with up to 25 needle punctures. Two knees had <5mm of medial opening in flexion after blade perforation. The mean pressure decreases in 90 degrees flexion, mid-flexion and extension were 11.2, 9.4 and 9.9 lbs respectively after 5 needle punctures and 8.1, 11.5 and 9.6 lbs between 5 and 15. Significant pressure decreases were seen after 5 and 10 needle punctures and again after blade perforation (p<0.05)

Needle puncture of the deep and superficial MCL leads to a significant and reliable decrease in medial tension over the first 15, with diminishing effect up to 25 punctures. This method may be employed when up to 20 lbs reduction in medial pressure is desired. Blade perforation after needle puncture should be approached with caution.

Introduction:

Total hip arthroplasty (THA) is extremely effective in treating debilitating arthritic conditions of the hip. With the many modular prosthetic designs available, surgeons can now precisely construct mechanical parameters such as femoral offset (FO). Although several studies have investigated relationships between offset choice and hip abductor strength, hip range of motion, and prosthetic wear rate, there is scarce data on the effect of FO on pain and functional outcomes following THA. The objective of this study was to assess the effect of restoring FO (within varying degrees compared to the contralateral non-diseased hip [CL]) on physical function, mental well-being, pain, and stiffness outcomes as measured by the Short Form 12 Health Survey (SF-12) and Western Ontario and McMaster University Osteoarthritis Index (WOMAC) at post-operative follow-up.

Introduction:

Unicompartmental knee arthroplasty (UKA) has been proven to be an effective treatment for degenerative joint disease confined to a single tibiofemoral compartment. Recently, UKAs have been performed with robotic-arm assistance (RAA) devices to build and improve upon previous computer-assisted navigation. As a pilot study, we have analyzed short term outcomes for a series of robotic-arm assisted medial UKAs and compared them to a comparable cohort of traditionally instrumented medial UKAs.

Indications for UKA for isolated osteoarthritis of the knee remain controversial. 229 UKA that were performed at our institution were evaluated for which factors was associated with a poor outcome. BMI > 35 was correlated with lower KSS scores than patients with BMI < 35. In contrast to prior reports, patients younger than 60 years old had higher scores than patients 60 years and older at 2 years. Women had an unacceptably high short-term revision rate for any reason of 6.5%. Popularity for UKA has increased, and a more in depth investigation of predictors of poor outcomes demonstrates that younger patients appear to have better results. Obese patients continue to improve up to 2 years after surgery and should not be precluded from undergoing UKA.

The study is a prospective series of the functional outcomes of total knee arthroplasty (TKA) with a novel bi-cruciate stabilizing prosthesis (BCS TKA) compared to a Posterior stabilized (PS) TKA. Between 2008 and 2012, 63 BCS TKA were performed on 56 patients (71 knees) and 54 patients underwent 56 PS TKA with a primary diagnosis of degenerative osteoarthritis, all performed by a single surgeon. Patients completed the Short-Form 12 and WOMAC Index questionnaires pre-operatively and post-operatively at 3 months, 1 year, and 2 years with range of motion determined in the office setting. Regarding the BCS knees, significant improvements in post-operative range of motion were noted, and results of the WOMAC pain component were promising at all intervals tested. However, measures of overall knee function including the WOMAC physical function and stiffness scores in addition to Knee Society Functional Scores saw a slight decline during the second post-operative year. Results from the PS knee implants showed similar trends, and no statistically significant differences were found between the two cohorts throughout functional follow-up; however the ranges of motions appear to be increased in the BCS knee cohort.

Not all patients receive enhanced mobility and return to comfortable, independent living after Total Hip Arthroplasty (THA). It would be beneficial to both surgeons and patients to be able to predict short term outcomes for THA. The purpose of this study was to investigate factors affecting the short term outcome of primary THA and develop a multivariate regression model that can predict such outcomes.

This was a prospective study of 101 patients, who underwent primary THA. All patients were followed for a minimum of 1 year. 12 independent variables, including age, gender, diagnosis, presence of preoperative comorbidities, BMI, preoperative WOMAC physical component (PC) score, type of anesthesia, type of fixation, surgical time, estimated blood loss, use of a postoperative drain, and length of stay were analyzed using correlation and multivariate regression analyses. Multivariate regression models were validated using an independent cohort.

Correlation analyses showed three variables significantly influence short term THA outcome. These include preoperative WOMAC PC score (PC) (p< 0.01), gender (G) (p= 0.01) and the presence of preoperative comorbidities (CMB) (p= 0.02). By multivariate regression analysis, the following regression model was obtained: Outcome = PC*0.45 −G*9 + CMB*8 + 62.

This model exhibited positive correlation (R2=.25) when compared to a separate cohort of 27 patients undergoing THA not included in the original equation derivation.

Our multivariate regression analysis has yielded statistical, multivariate confirmation or non-confirmation of common, predictive THA factors that have previously been reported in the literature. This study provides a concrete, statistically significant measure indicating that preoperative WOMAC PC score, gender, and the presence of preoperative comorbidities are predictive factors for short term primary THA outcome. Finally, our multivariate regression equation can be used to predict the general short term patient outcome following primary THA.

Background: Abductor failure after total hip arthroplasty is a rare but debilitating problem. The diagnosis is difficult, and when recognized, there are few successful treatment options. The purpose of this study is to review our experience with a new surgical technique using fresh-frozen Achilles tendon allograft with an attached calcaneal bone graft to reconstruct a deficient abductor mechanism after total hip arthroplasty.

Methods: From 2003 to 2006, we performed seven abductor reconstructions with Achilles tendon allograft for patients with abductor deficiency after total hip arthroplasty. Four patients had a prior posterior approach and three had a prior anterolateral approach. At a mean of 29 months from index procedure, all seven patients suffered from symptoms of lateral hip pain and abductor weakness as documented by positive Trendelenburg sign, limp, and limited motor strength with side-lying abduction. Hip arthrograms were obtained in five of seven patients.

Results: The average pre-reconstruction Harris Hip Score was 34.7 and average pain score was 11.4. All five hip arthrograms showed extravasation of dye over the greater trochanter, confirming the diagnosis of a bald greater trochanter and massive abductor loss found at time of surgery. At a minimum 24 month follow-up and an average follow-up of 31 months, the post-reconstruction Harris Hip Score was 85.9 and the average pain score was 38.9.

Conclusions: Abductor reconstruction with Achilles tendon allograft using calcaneal bone block fastened to the greater trochanter has offered significant relief of pain and improvement in function at early follow-up in this series of patients.

Purpose: Patients undergoing total knee arthroplasty (TKA) often experience a difficult recovery due to severe post-operative pain. Utilizing a multi-modal pain management protocol, a blinded, randomized, placebo-controlled study was designed to evaluate the efficacy of patient selected music on reducing perceived pain.

Method: Using a standardized intra-operative anesthetic protocol and postoperative pain management protocol, consented patients were randomized into either: 1) the interventional Music group (noise-reduction headphones, patient choice/classical music) or the control, Non-Music group (noise-reduction headphones only). Pain scores, aided by the Wong-Baker and Verbal Descriptor scales, were assessed via the Visual Analog Scale (VAS) at baseline and postoperatively at 3, 6, and 24 hours. A paired Student’s t-test was utilized to determine statistical significance, which was set at a p < 0.05.

Results: Thirty subjects were enrolled. At baseline, there were no statistical differences in mean pain between the study (2.29 ± 2.78) and the control (3.34 ± 2.67) groups (p = 0.19). Mean pain scores reported the Music group to have significantly less pain at 3 hours (1.49 ± 1.39 vs. 3.87 ± 3.44, p = 0.01), and at 24 hours (2.41 ± 1.67 vs. 4.03 ± 2.89, p=0.04).

Conclusion: Intraoperative music provides an inexpensive, non-invasive method of lowering perceived postoperative pain for patients undergoing a TKA. The results of this study offer a glimpse into how an alternative therapy or non-pharmacologic method can reduce postoperative pain. A larger-scale, higher powered trial may demonstrate how music could favorably affect secondary outcomes such as patient satisfaction, range of motion, and length of stay.

In May 2006, the US FDA approved the first type of metal-on-metal hip resurfacing (MOMHR) for distribution in the US because of promising survivorship achieved in Europe for patients with a diagnosis of primary osteoarthritis. No long-term US survivorship data currently exists for the Birmingham Hip Resurfacing (BHR) implant. The purpose of this study was to demonstrate early efficacy with validated outcome measures and survivorship comparable to total hip arthroplasty (THA).

A cohort of 79 consecutive MOMHR patients was compared to a similar cohort of 71 THA patients, controlling for age, gender and comorbidities. Mean f/u was 14.1±5 mos (range 12–24 mos). The mean age for the MOMHR group was 50±9 yrs, and mean body mass index (BMI) was 29±5. The THA group had a mean age of 52±9 yrs and a mean BMI of 30±6. Outcomes were prospectively assessed with the SF-12 and WOMAC.

For both groups, pre-op pain and function scores were similar. At 1 yr f/u, MOMHR showed significantly more improvement (p< 0.05) in stiffness, pain and physical function compared to the THA. The overall complication rate was 7% in the MOMHR group and 9% in the THA group. There were no instances of displaced femoral neck fracture, component loosening, dislocation or chronic deep infection in any patient in the MOMHR cohort.

These early results are promising, but longer-term follow-up is needed to properly compare MOMHR to THA which remains the current gold standard.