Success of High Tibial Osteotomy in the United States Military

Management Considerations for Unicompartmental Osteoarthritis in Athletic Populations: A Review of the Literature

Unicompartmental osteoarthritis in the young athlete poses a challenge for both patients and providers. Coronal plane malalignment is frequently a concomitant finding that adds to the complexity of management. Military surgeons are presented unique challenges, in that they must consider optimal joint-preservation methods while returning patients to a high-demand occupational function. Management options range from lifestyle changes to surgical interventions. We present a concise review of the available literature on this subject, with a specific focus on indications and outcomes within the military and young athletic population.

Timing of Outcomes and Expectations After Knee Surgery in the US Military: A Systematic Review

CONTEXT

Knee injury and subsequent surgery are widespread in the military setting. Associations between knee surgery and expected outcomes over time have not been consolidated and characterized systematically by procedure type across the body of literature, and the temporal expectations of these outcomes remain unclear.

OBJECTIVE

To summarize common postoperative follow-up times and associated outcomes that determine clinical or surgical failure in US service members after elective knee surgery.

DATA SOURCES

A systematic search was conducted with 3 bibliographic databases of published research reports from 2010 through 2021.

STUDY SELECTION

Studies in US military service members undergoing elective knee surgery, with a minimum of 1-year follow-up, and reporting on a functional/occupational outcome were included. Three reviewers screened all abstracts and full-text articles to determine eligibility.

STUDY DESIGN

Systematic review of longitudinal cohort studies.

LEVEL OF EVIDENCE

Level 2a.

DATA EXTRACTION

Extracted data included military demographics, surgical procedure variables, surveillance period, and outcome measures. The Newcastle-Ottawa Scale and the Grading of Recommendations Assessment, Development, and Evaluation approach were used to determine study quality and risk of bias.

RESULTS

A total of 22 studies (mean follow-up time of 40.7 months) met the inclusion criteria. For cruciate ligament repair, approximately one-third of patients required a second surgery or were medically separated from military service by 2 years from surgery; 100% were reinjured by 4 years, and 85% sustained a new injury within 5 years of surgery. For meniscal repair, nearly one-third of patients were medically separated, and half were placed on activity restrictions within 3 years of surgery. For articular cartilage repair, within 5 years, 39% of patients required a second surgery, 30% were placed on activity restrictions, and 36% were medically separated. For patellar repair, 37% of patients were medically separated and over half were placed on activity restrictions within 5 years.

CONCLUSION

Common knee surgeries can have long-term implications for military careers that may not become apparent with shorter follow-up periods (<2 years). When longer surveillance periods are used (eg, up to 5 years), additional surgical procedures are more common and the likelihood of being injured or medically separated from military service is higher.

Predicting Postoperative Injury and Military Discharge Status After Knee Surgery in the US Army

BACKGROUND

Researchers have assessed postoperative injury or disability predictors in the military setting but typically focused on 1 type of surgical procedure at a time, used relatively small sample sizes, or investigated mixed cohorts with civilian populations.

PURPOSE

To identify the relationship between baseline variables and injury incidence or military discharge status in US Army soldiers after knee surgery.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Data were obtained from a repository containing personnel, performance, and medical records for all active-duty US Army soldiers. Multivariate logistic regressions were used to estimate the effects of numerous variables on postoperative injury or on medical discharge. Variable selection and model validation were conducted using the k-fold method.

RESULTS

A total of 7567 soldiers underwent knee surgery between 2017 and 2019. Meniscal procedures were the most common type of surgery (39%), and approximately 71% of the cohort had a postoperative injury. Significant predictors for sustaining a postoperative injury included having a previous nonknee injury (odds ratio [OR], 1.5), female sex (OR, 1.3), and Black race (OR, 1.2). Within 4 years after surgery, 17% of soldiers were discharged from the military because of knee-related disability. Significant predictors for discharge from duty included enlisted rank (OR, 2.3), recent fitness test failure (OR, 1.9), number of previous knee surgeries (OR, 1.7), and having a previous nonknee injury (OR, 1.6).

CONCLUSION

After knee surgery, nearly three-fourths of the soldiers in this cohort sustained a postoperative injury and almost one-fifth of soldiers were medically discharged from the military within 4 years. This study identified variables that indicate statistically increased risk for these postoperative outcomes and highlighted potentially modifiable factors.

Return to Work and Sport After Proximal Tibial Osteotomy and the Effects of Opening Versus Closing Wedge Techniques on Adverse Outcomes: A Systematic Review and Meta-analysis

BACKGROUND

Although many studies have reported successful functional outcomes after proximal tibial osteotomy (PTO), a paucity of literature has sought to quantify outcomes and current rates of return to sport (RTS) and return to work (RTW) after PTO.

PURPOSE

To (1) determine current rates of RTS and RTW after PTO and (2) quantify the incidence of complications and conversion to total knee arthroplasty (TKA) after PTO for all patients as well as those undergoing opening and closing wedge PTO.

STUDY DESIGN

Systematic review and meta-analysis; Level of evidence, 4.

METHODS

The Cochrane Database of Systematic Reviews, the Cochrane Central Register of Controlled Trials, PubMed (2008-2019), EMBASE (2008-2019), and MEDLINE (2008-2019) databases were queried. Data pertaining to article information, patient demographics, surgical techniques, rates of complication and conversion to TKA, patient-reported outcome scores, RTS, and RTW were extracted. Data were synthesized, and a random effects meta-analysis of proportions using continuity correction methods was performed to determine the proportion of patients receiving opening and closing wedge PTO who experienced adverse events.

RESULTS

The review and meta-analysis included 33 studies involving 1914 patients who underwent PTO with a weighted mean ± SD age of 50.3 ± 9.9 years and body mass index of 26.9 ± 2.3 kg/m². The pooled RTS and RTW rates were 75.7% (range, 55%-100%) in 814 patients and 80.8% (range, 41%-100%) in 505 patients, respectively. The pooled TKA rate was 12.5% (range, 0%-35.7%) at a mean of 70.6 months and the pooled complication rate was 11.1% (range, 0%-28.6%). The overall random pooled summary estimate of the proportion of patients who underwent opening wedge PTO and subsequently converted to TKA was 2.0% (95% CI, 1.0%-4.0%; I² = 63.65) at a mean of 43.4 ± 31.9 months and who experienced a complication was 6.0% (95% CI, 3.0%-9.0%; I² = 87.10%). For closing wedge PTO, the proportion of patients who converted to TKA was 5.0% (95% CI, 1.0%-9.0%; I² = 93.1%) and experienced a complication was 2.0% (95% CI, 1.0%-3.0%; I² = 90.0%). Only 53.8% of studies that referenced RTS provided postoperative RTS rates, and 80% of studies that referenced RTW provided RTW rates. Only 1 study defined RTS criteria, no studies defined RTW criteria, and 31 different outcome measures were reported across all studies.

CONCLUSION

Patients undergoing PTO for osteoarthritis, cartilage defects, and symptomatic malalignment of the knee experience high rates of RTS and RTW. These patients also experience low rates of complications and conversion to TKA, regardless of opening or closing wedge technique. Significant heterogeneity exists with regard to criteria used to define RTS and RTW and patient-reported outcome measures used to assess clinical and functional improvements after PTO.

Effect of proximal abducting ulnar osteotomy (PAUL) on frontal plane thoracic limb alignment: An ex vivo canine study

OBJECTIVE

To determine the effect of proximal abducting ulnar osteotomy (PAUL) on frontal plane thoracic limb alignment in standing and recumbent positions.

STUDY DESIGN

Ex vivo cadaveric study.

SAMPLE POPULATION

Canine thoracic limbs (n = 15 limb pairs).

METHODS

Limbs were acquired from healthy Labrador retrievers that had been euthanized for reasons unrelated to this study. A limb press was used to obtain standing and recumbent caudocranial radiographs before and after PAUL. Foot lateralization and rotation were directly measured in standing position. Mechanical joint angles were determined using full limb radiographic montages and the center of rotation of angulation (CORA) method for pre-PAUL (Pre), 2-mm PAUL (PAUL2), and 3-mm PAUL (PAUL3). Data are reported as mean ± SD and 95% CI. Mixed linear modeling was used to identify differences in limb alignment values and foot position, with significance established at P ≤ .004.

RESULTS

There were differences in five of 12 limb alignment values pre-PAUL and post-PAUL in standing and recumbent positions. In the standing position, there was an increase in mechanical medial proximal radioulnar angle (Pre, 80.6° ± 2.5°; PAUL2, 82.6° ± 2.4°; PAUL3, 84° ± 2.4°) and a decrease in elbow compression angle (Pre, 1.4° ± 1.3°; PAUL2, 1° ± 0.9°; PAUL3, 0.8° ± 1°). There was a movement of mechanical humeral radioulnar angle (Pre, -8.9° ± 2.8°; PAUL2, -6.1° ± 2.7°; PAUL3, -5.2 ± 2.7°), mechanical thoracic humeral angle (Pre, 3.9° ± 1.7°; PAUL2, 2.4° ± 1.4°; PAUL3, 2.6° ± 1.5°), and elbow mechanical axis deviation (Pre, 1.9% ± 1.1%; PAUL2, 0.9% ± 1.1%; PAUL3, 0.4% ± 1.4%) toward a value of "0" representing coaxial alignment of the limb. The foot underwent lateralization (Pre, 1.4 ± 0.6 cm; PAUL2, 1.8 ± 0.7 cm; PAUL3, 2.3 ± 0.7 cm) and external rotation (Pre, 10.5° ± 4.7°; PAUL2, 13.7° ± 5.1°; PAUL3, 16° ± 6.6°).

CONCLUSION

In the ex vivo setting, PAUL resulted in translation of the mechanical axis of the thoracic limb from a medial to lateral direction through alterations in limb alignment values associated with the elbow, humerus, and proximal radius/ulna.

CLINICAL SIGNIFICANCE

Additional studies are required to determine whether PAUL alters thoracic limb alignment in client-owned dogs.

Return to Work Following High Tibial Osteotomy With Concomitant Osteochondral Allograft Transplantation

PURPOSE

To assess the timeline of return to work (RTW) following opening-wedge high tibial osteotomy (HTO) with concomitant osteochondral allograft transplantation (OCA) of the medial femoral condyle.

METHODS

Consecutive patients undergoing HTO + OCA due to focal chondral deficiency and varus deformity were retrospectively identified and reviewed at a minimum of 2 years following surgery. Patients completed a subjective work questionnaire, a visual analog scale for pain, Single Assessment Numerical Evaluation, and a satisfaction questionnaire.

RESULTS

Twenty-eight patients (average age: 36.0 ± 7.9 years) were included at 6.7 ± 4.1 years postoperatively. Twenty-six patients were employed before surgery and 25 patients (96.2%) returned to work following HTO + OCA. However, only 88.5% of patients were able to return to the same level of occupational intensity by 3.5 ± 2.9 months postoperatively. The rate of RTW to the same occupational intensity for sedentary, light, medium, and heavy intensity occupations was 100%, 100%, 88.9%, and 80% (P = .8), whereas the duration of RTW was 9.0 ± 7.1 months, 1.7 ± 1.4 months, 2.7 ± 0.9 months, and 4.2 ± 1.9 months (P = .006), respectively. Two patients (7.7%) underwent knee replacement by 5.3 ± 3.1 years postoperatively due to progression of osteoarthritis in the medial compartment.

CONCLUSIONS

In patients with focal chondral deficiency and varus deformity, HTO + OCA provides a high rate of RTW (96.2%) by 3.5 ± 2.9 months postoperatively. However, patients with greater-intensity occupations may take longer to return to work than those with less physically demanding occupations.

LEVEL OF EVIDENCE

IV, Retrospective Case Series.

Distal femoral osteotomy in a young symptomatic population: Outcomes correlate to concomitant pathology

Background

There is a paucity of literature describing distal femoral osteotomies (DFO) in regards to complications and outcomes with previously studied cohorts containing primarily older, arthritic subjects. There has been no study to date focusing on younger, pre-arthritic patients.

Methods

All service members indicated for distal femoral osteotomy for coronal plane malalignment were isolated from military treatment centers between 2007 and 2013. Demographic and surgical variables were extracted, and perioperative complications, clinical course, and return to military function were extracted using clinical notes and radiographs.

Results

A total of 22 knees in 19 patients were identified at an average 3.2 year follow-up, with the exclusion of 16 individuals. Statistical analysis revealed worse outcomes associated with smoking, over correction, breach of the medial cortex, and prior surgeries. Overall 58% of patients left the military as the result of knee dysfunction despite an average improvement in visual analog scores (VAS) from 4.0 to 1.9 (p = 0.004).

Conclusions

While offloading the lateral compartment improves symptoms at short to midterm follow-up preventing progression to arthroplasty, young active duty military members have suboptimal return to duty rates.

Development and validation of a finite element model to simulate the opening of a medial opening wedge high tibial osteotomy

Medial opening wedge high tibial osteotomy (MOWHTO) is a surgical procedure intended to alter the coronal and sagittal plane alignment of the lower limb to primarily relieve the symptoms of osteoarthritis in the medial compartment of the knee. The purpose of this work was to develop and validate a finite element model to simulate the opening of a high tibial osteotomy and determine whether a pilot hole at the cortical hinge reduces the risk of lateral cortical fracture. Fifteen models were reconstructed from CT images of eight cadaveric specimens. The validated models indicated that the addition of the pilot hole increased the stresses and likelihood of a type-I and type-II fractures during the opening of a medial open wedge high tibial osteotomy compared to the no-hole condition.

Can osteoarthritic patients with mild varus deformity be indicated for high tibial osteotomy?

BACKGROUND

Whether osteoarthritic patients with mild varus deformity can be indicated for high tibial osteotomy (HTO) is not established. We examined the preoperative characteristics and postoperative outcomes of HTO in patients with mild genu varum compared to patients with greater varus deformity.

METHODS

Seventy-one patients who underwent HTO were included in this retrospective study. Patients were divided into either mild varus (MV, mechanical femorotibial angle (mFTA) ≤4°, n = 31 (44%)) and greater varus (GV, mFTA >4°, n = 40 (56%)) groups. Preoperative characteristics on single photon emission computed tomography-computed tomography (SPECT-CT), magnetic resonance image and radiograph were evaluated. Alignment parameters and functional outcomes were compared pre- and postoperatively between the groups.

RESULTS

Preoperative characteristics were similar between the two groups, except the severity of arthritis and coronal alignment. There was no difference in the proportion of hot uptake in the medial compartment; medial meniscus posterior horn root tear, complex or radial tear; bone marrow edema. Full-thickness cartilage defect of medial compartment was more frequent and arthritis grade was also more severe in GV group. Coronal alignment of the MV group was corrected into more valgus than the GV group (4.5° vs. 2.8° in mFTA, P = 0.012). Pre- and postoperative Knee Society knee and function scores were also comparable in the two groups.

CONCLUSIONS

Mild varus patients are similar to greater varus patients regarding preoperative features and achieve the comparable functional outcome. A selected subset of osteoarthritic patients with mild varus deformity might be indicated for HTO.

LEVEL OF EVIDENCE

III (Retrospective comparative study).

Comparative Effectiveness of Intra-Articular Hyaluronic Acid and Corticosteroid Injections on the Time to Surgical Knee Procedures

BACKGROUND

Use of intra-articular hyaluronic acid (HA) injections to manage knee osteoarthritis (OA) remains controversial because of weak and conflicting evidence. The objective was to evaluate the effectiveness of intra-articular HA injections for knee OA management.

METHODS

A nested cohort of persons with knee OA seeing a specialist was created using a 10% random sample of LifeLink Plus claims (2010-2015) to compare the risk of composite (any) knee surgical interventions, total (TKA)/unicompartmental knee arthroplasty (UKA) and TKA only among HA users and 2 comparison groups: corticosteroid (CS) users and HA/CS nonusers. A high-dimensional propensity score (hdPS) was used to match HA users with CS users and with HA/CS nonusers on background covariates. The risk of surgical interventions among HA users relative to the comparison groups was assessed using Cox proportional hazard models.

RESULTS

Among 13,849 patients, 797 were HA users, 5327 were CS users, and 7725 were HA/CS nonusers. After hdPS matching, the risk of composite surgical interventions did not differ between HA users and HA/CS nonusers (hazard ratio [HR], 0.88; 95% confidence interval [CI], 0.67-1.16) and CS users (HR, 0.89; 95% CI, 0.65-1.12). Seven of the 8 sensitivity analyses demonstrated no significant benefit among HA users compared to CS users and HA/CS nonusers. A sensitivity analysis that restricted the study cohort to those who ultimately have knee surgery showed a lower risk of surgery of HA (HR, 0.87; 95% CI, 0.79-0.95).

CONCLUSION

There were no significant differences in the risk of surgical interventions among HA users compared to HA/CS nonusers and CS users after accounting for residual confounding using an hdPS.

High Rates of Return to Sports Activities and Work After Osteotomies Around the Knee: A Systematic Review and Meta-Analysis

BACKGROUND

Knee osteotomies are proven treatment options, especially in younger patients with unicompartmental knee osteoarthritis, for certain cases of chronic knee instability, or as concomitant treatment for meniscal repair or transplantation surgery. Presumably, these patients wish to stay active. Data on whether these patients return to sport (RTS) activities and return to work (RTW) are scarce.

OBJECTIVES

Our aim was to systematically review (1) the extent to which patients can RTS and RTW after knee osteotomy and (2) the time to RTS and RTW.

METHODS

We systematically searched the MEDLINE and Embase databases. Two authors screened and extracted data, including patient demographics, surgical technique, pre- and postoperative sports and work activities, and confounding factors. Two authors assessed methodological quality. Data on pre- and postoperative participation in sports and work were pooled.

RESULTS

We included 26 studies, involving 1321 patients (69% male). Mean age varied between 27 and 62 years, and mean follow-up was 4.8 years. The overall risk of bias was low in seven studies, moderate in ten studies, and high in nine studies. RTS was reported in 18 studies and mean RTS was 85%. Reported RTS in studies with a low risk of bias was 82%. No studies reported time to RTS. RTW was reported in 14 studies; mean RTW was 85%. Reported RTW in studies with a low risk of bias was 80%. Time to RTW varied from 10 to 22 weeks. Lastly, only 15 studies adjusted for confounders.

CONCLUSION

Eight out of ten patients returned to sport and work after knee osteotomy. No data were available on time to RTS. A trend toward performing lower-impact sports was observed. Time to RTW varied from 10 to 22 weeks, and almost all patients returned to the same or a higher workload.

Comparison of Low-, Moderate-, and High-Molecular-Weight Hyaluronic Acid Injections in Delaying Time to Knee Surgery

BACKGROUND

We compared the effectiveness of low-molecular-weight (MW) hyaluronic acid (HA) injections (LMWHA), moderate-MW HA injections (MMWHA), and high-MW HA injections (HMWHA) for prevention or delay of knee surgery in patients with knee osteoarthritis.

METHODS

An observational cohort study using LifeLink Plus claims (2006-2015) was used. The primary outcome measure of the study included all surgical interventions of the knee. The secondary outcome measures were the following: (1) unicompartmental knee arthroplasty or total knee arthroplasty and (2) total knee arthroplasty only. A high-dimensional propensity score (hdPS) using 1:1 matching was used to adjust for confounding. The likelihood of each outcome was assessed using Cox proportional hazard models.

RESULTS

A cohort of 30,417 incident HA users with knee osteoarthritis met our inclusion-exclusion criteria. There was no difference in the likelihood of composite surgical events between LMWHA users (hazard ratio, 0.939; 95% confidence interval, 0.870-1.013) and MMWHA users (hazard ratio, 1.032; 95% confidence interval, 0.952-1.119) when compared with HMWHA users in a matched hdPS analysis. However, a significantly lower likelihood for all outcome measures was demonstrated in LMWHA and MMWHA users compared with HMWHA users when hdPS was not used.

CONCLUSION

There was no significant difference in the likelihood of surgical interventions between LMWHA, MMWHA, and HMWHA users after accounting for empirically derived confounders.

Return to Preoperative Function After Autologous Cartilage Implantation of the Knee in Active Military Servicemembers

BACKGROUND

Autologous chondrocyte implantation (ACI) has been shown to provide adequate durability, pain relief, and improved long-term functional outcomes in the average patient, but proof of its efficacy in individuals with greater than average physical demands is scarce. Further knowledge is required to understand which patients may benefit from ACI and to identify which risk factors are associated with failure to return to the preinjury activity level.

PURPOSE

To determine the occupational outcomes, rates of reoperation, and variables predictive of suboptimal outcomes after ACI.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

All active-duty military servicemembers in the United States who underwent ACI of the knee between 2004 and 2014 were identified. Demographic information, injury characteristics, surgical variables, and clinical and surgical outcomes were extracted from the medical record. Univariate and multivariate analyses were used to determine significant independent predictors of clinical and surgical failures.

RESULTS

A total of 90 patients (91 knees) met the inclusion criteria. The cohort was predominantly male (86%), with a mean age of 34.5 ± 6.3 years (range, 20-50 years). The most common location of the articular cartilage lesion was the patellofemoral compartment (54 lesions, 59%), and the mean Outerbridge grade and size were 3.8 ± 0.4 and 4.00 ± 2.77 cm² (range, 1.2-15.0 cm²), respectively. A total of 72 patients (79%) had at least 1 previous knee procedure. Nearly three-quarters of patients (71%) underwent concomitant procedures. At a mean follow-up of 59.9 ± 27.1 months (range, 24.0-140.1 months), 60% of our patients reported significant improvement in knee pain and did not require further surgical intervention. Multivariate analysis identified age <30 years as the only significant independent predictor of both clinical (P = .011) and overall failure (P = .014). Moderate-demand military occupational specialties (P = .036), exclusive involvement of the patellofemoral compartment (P = .045), and use of a periosteal patch (P = .0173) were additionally found to be independent predictors of surgical failure.

CONCLUSION

Treatment of articular cartilage defects of the knee with ACI in physically active young individuals can return nearly two-thirds of individuals to daily activity with decreased pain and improved function. Risk factors for failure after ACI surgery were age younger than 30 years, lower demand occupation, exclusive involvement of the patellofemoral compartment, prior microfracture, and use of a periosteal patch.

Return to Work and Sport Following High Tibial Osteotomy: A Systematic Review

BACKGROUND

The purpose of this study was to examine (1) timelines for return to sport and work following high tibial osteotomy (HTO), and (2) whether patients return to sport and work at levels similar to preoperative levels.

METHODS

A systematic search was conducted across 3 databases (MEDLINE, Embase, and PubMed). Two reviewers independently screened the results for relevant articles. Data regarding patient demographics, indications, surgical technique, return to work and sport, and complication and failure rates were abstracted from eligible studies.

RESULTS

Nineteen studies were included, involving 1,189 patients (64% male, 21% female, 15% unspecified) and 1,224 knees. Mean age was 46.2 years (range, 16 to 80 years). Opening-wedge HTO was most commonly used, followed by closing-wedge HTO and hemicallotasis. Mean follow-up was 65.4 months (range, 8 to 253 months). Overall, 87.2% of patients returned to sport postoperatively, and 78.6% returned at an equal or greater level. Among competitive athletes, 54% returned to competition. Overall, 84.5% of patients returned to work postoperatively, and 65.5% returned at an equal or greater level. Approximately 90% of patients who returned to work or sport did so within 1 year. The complication rate was 5.8%, with infection being the most common complication; 7.0% of patients progressed to a total knee arthroplasty at a mean of 6.7 years (range, 0.8 to 15 years) following HTO.

CONCLUSIONS

The majority of patients undergoing HTO return to sport and work, and most return within 1 year of the operation. Most patients return to sport at a level equal to or greater than the preoperative level. Approximately two-thirds of patients return to an equal or greater level of physical work.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.