Coexisting lumbar spondylosis in patients undergoing TKA: how common and how serious?

Characteristics associated with comorbid lumbar spinal stenosis symptoms in people with knee or hip osteoarthritis: an analysis of 9,136 good life with osteoArthritis in Denmark (GLA:D®) participants

BACKGROUND

Previous studies have found that lumbar spinal stenosis (LSS) often co-occurs with knee or hip OA and can impact treatment response. However, it is unclear what participant characteristics may be helpful in identifying individuals with these co-occurring conditions. The aim of this cross-sectional study was to explore characteristics associated with comorbid symptoms of lumbar spinal stenosis (LSS) in people with knee or hip osteoarthritis (OA) enrolled in a primary care education and exercise program.

METHODS

Sociodemographic, clinical characteristics, health status measures, and a self-report questionnaire on the presence of LSS symptoms was collected at baseline from the Good Life with osteoArthritis in Denmark primary care program for knee and hip OA. Cross-sectional associations between characteristics and the presence of comorbid LSS symptoms were assessed separately in participants with primary complaint of knee and hip OA, using domain-specific logistic models and a logistic model including all characteristics.

RESULTS

A total of 6,541 participants with a primary complaint of knee OA and 2,595 participants with a primary complaint of hip OA were included, of which 40% and 50% reported comorbid LSS symptoms, respectively. LSS symptoms were associated with similar characteristics in knee and hip OA. Sick leave was the only sociodemographic variable consistently associated with LSS symptoms. For clinical characteristics, back pain, longer symptom duration and bilateral or comorbid knee or hip symptoms were also consistently associated. Health status measures were not consistently related to LSS symptoms.

CONCLUSION

Comorbid LSS symptoms in people with knee or hip OA undergoing a primary care treatment program of group-based education and exercise were common and associated with a similar set of characteristics. These characteristics may help to identify people with co-occurring LSS and knee or hip OA, which can be used to help guide clinical decision-making.

Biomechanical and clinical relationships between lower back pain and knee osteoarthritis: a systematic review

BACKGROUND

Osteoarthritis (OA) and lower back pain (LBP) are most common health problems which lead to pain and disability. This study aimed to systematically review the evidence to find any relationship between knee osteoarthritis (KOA) and LBP or any potential causation.

METHODS

The databases of Scopus, MEDLINE, and Embase were searched from inception to 01 October 2022. Any study published in English assessing live humans over 18 years with KOA and LBP was eligible to be included. Studies were independently screened by two researchers. Data of the included studies were extracted based on the participants, outcomes related to knee and lumbar spine, reported association or causation between LBP and KOA, and study design. Data were narratively analyzed and presented as graphs and table. Methodology quality was assessed.

RESULTS

Of 9953 titles and abstracts, duplicates were removed, and 7552 were screened. Altogether, 88 full texts were screened, and 13 were eligible for the final inclusion. There were some biomechanical and clinical causations were observed for the concurrent presence of LBP and KOA. Biomechanically, high pelvic incidence is a risk factor for development of spondylolisthesis and KOA. Clinically, knee pain intensity was higher in KOA when presents with LBP. Less than 20% of studies have justified their sample size during the quality assessment.

DISCUSSION

Development and progression of KOA in patients with degenerative spondylolisthesis may be induced by significantly greater mismatches of lumbo-pelvic sagittal alignment. Elderly patients with degenerative lumbar spondylolisthesis and severe KOA reported a different pelvic morphology, increased sagittal malalignment with a lack of lumbar lordosis due to double-level listhesis, and greater knee flexion contracture than in patients with no to mild and moderate KOA. People with concurrent LBP and KOA have reported poor function with more disability. Both LBP and lumbar kyphosis indicate functional disability and knee symptoms in patients with KOA.

CONCLUSIONS

Different biomechanical and clinical causations were revealed for the concurrent existence of KOA and LBP. Therefore, careful assessment of both back and knee joints should be considered when treating KOA and vice versa.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42022238571.

Spondylolisthesis and mismatch deformity affect outcomes after total knee arthroplasty

BACKGROUND

Little published data currently exist regarding the potential relationships between spondylolisthesis, mismatch deformity, and clinical outcomes following total knee arthroplasty (TKA). We hypothesize that preexisting spondylolisthesis will result in decreased functional outcomes after TKA.

METHODS

This retrospective cohort comparison of 933 TKAs was performed between January 2017 and 2020. TKAs were excluded if they were not performed for primary osteoarthritis (OA) or if preoperative lumbar radiographs were unavailable/inadequate to measure the degree of spondylolisthesis. Ninety-five TKAs were subsequently available for inclusion and divided into two groups: those with spondylolisthesis and those without. Within the spondylolisthesis cohort, pelvic incidence (PI) and lumbar lordosis (LL) were calculated on lateral radiographs to determine the difference (PI-LL). Radiographs with PI-LL > 10° were then categorized as having mismatch deformity (MD). The following clinical outcomes were compared between the groups: need for manipulation under anesthesia (MUA), total postoperative arc of motion (AOM) both pre-MUA or post-MUA/revision, incidence of flexion contracture, and a need for later revision.

RESULTS

Forty-nine TKAs met the spondylolisthesis criteria, while 44 did not have spondylolisthesis. There were no significant differences in gender, body mass index, preoperative knee range of motion (ROM), preoperative AOM, or opiate use between the groups. TKAs with spondylolisthesis and concomitant MD were more likely to have MUA (p = 0.016), ROM < 0-120 (p < 0.014), and a decreased AOM (p < 0.02) without interventions.

CONCLUSION

Preexisting spondylolisthesis by itself may not have adverse effect clinical results following TKA. However, spondylolisthesis increases the likelihood of developing MD. In those with both spondylolisthesis and concomitant mismatch deformities, patients had statistically and clinically significantly decreased in postoperative ROM/AOM and increased need for MUA. Surgeons should consider clinical/radiographic assessments of patients with chronic back pain who present for total joint arthroplasty.

LEVEL OF EVIDENCE

Level 3.

Associations between comorbid lumbar spinal stenosis symptoms and treatment outcomes in 6,813 patients with knee or hip osteoarthritis following a patient education and exercise therapy program

Objective

People with knee or hip osteoarthritis (OA) can experience comorbid lumbar spinal stenosis (LSS), but the impact on treatment outcomes is unknown. The aim of this study was to investigate associations between comorbid LSS symptoms and changes in pain, function, and quality of life following a patient education and exercise therapy program.

Design

This was a longitudinal analysis of 6813 participants in the Good Life with osteoArthritis in Denmark (GLA:D®) program; a structured patient education and exercise therapy program for knee and hip OA. Participants were classified as having comorbid LSS symptoms based on self-report symptom items. Linear mixed models were used to assess differences in change in pain, function, and quality of life outcomes (0 worst to 100 best) at 3- and 12-month follow-up.

Results

15% and 23% of knee and hip OA participants had comorbid LSS symptoms, respectively. Knee participants with comorbid LSS symptoms had smaller improvement in pain at 3-months (-1.7, 95% CI -3.3 to -0.1) and hip participants with comorbid LSS symptoms had greater improvement in function at 3- (2.5, 95% CI 0.5 to 5.0) and 12-months (3.8, 95% CI 0.9 to 6.6), when compared to those without LSS symptoms. These differences were not clinically significant and no differences in other outcomes were observed.

Conclusion

Knee or hip OA patients with comorbid LSS symptoms should expect similar improvements in knee- or hip-related pain, function, and quality of life outcomes when undergoing a patient education and exercise therapy program compared to those without LSS symptoms.

Presence of back pain prior total knee arthroplasty and its effects on short-term patient-reported outcome measures

PURPOSE

Back pain may both decrease patient satisfaction after TKA and confound outcome assessment in satisfied patients. Our primary objective was to determine whether preoperative back pain is associated with differences in postoperative patient-reported outcome measures (PROMs).

METHODS

We retrospectively reviewed 234 primary TKA patients who completed PROMs preoperatively and 12 weeks postoperatively, which included a back pain questionnaire, the Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS JR) and the Forgotten Joint Score-12 (FJS-12). Cohorts were defined based on the severity of preoperative back pain (none, mild, moderate and severe) and compared. Demographics were compared using ANOVA and Chi-square analysis. Univariate ANCOVA analysis was utilized to compare PROMs while accounting for significant demographic differences.

RESULTS

Both preoperative KOOS JR scores (none: 47.90, mild: 47.61, moderate: 44.61 and severe: 38.70; p = 0.013) and 12-week postoperative KOOS JR scores (none: 61.24, mild: 64.94, moderate: 57.48 and severe: 57.01; p = 0.012) had a statistically significant inverse relationship with regard to the intensity of preoperative back pain. Although FJS-12 scores at the 12-week postoperative period trended lower with increasing levels of preoperative back pain (p = 0.362), it did not reach statistical significance. Patients who reported severe back pain preoperatively achieved the largest delta improvement from baseline compared to those with lesser pain intensity (p = 0.003). Patients who had a 2-grade improvement in their back pain achieved significantly higher KOOS JR scores 12 weeks postoperatively compared to patients with either 1-grade or no improvement (63.53 vs. 55.98; p = 0.042). Both preoperative (47.99 vs. 41.11; p = 0.003) and 12-week postoperative (64.06 vs. 55.73; p < 0.001) KOOS JR scores were statistically higher for those who reported mild or no back pain pre-and postoperatively than those who reported moderate or severe back pain pre-and postoperatively.

CONCLUSION

Knee pain and back pain both exert negative effects on outcome instruments designed to measure pain and function. Although mean improvement from pre- to postoperative KOOS JR scores for patients with severe pre-existing back pain was higher than their counterparts, this statistical difference is likely not clinically significant. This implies that all patients may experience similar benefits from TKA despite the presence or absence of back pain. Attempts to measure TKA outcomes using PROMs should seek to control for lumbago and other sources of body pain. Level of Evidence IIIRetrospective Cohort Study.

Relationships between the changes in flexion contracture and standing flexion angle of the knee and sagittal spinal alignment after total knee arthroplasty

BACKGROUND

The sagittal spinal alignment interacts with the lower extremity in patients with combined degenerative disease of the spine and lower extremity. This study aimed to clarify the relationships between the reciprocal changes in sagittal alignment of the knee, pelvis, and spine after total knee arthroplasty (TKA) in osteoarthritis patients.

METHODS

Prospectively, 36 patients who underwent primary TKA for severe knee osteoarthritis were enrolled. Their clinical and radiological evaluation included assessments of the knee flexion contracture (KFC) and standing knee flexion angle (KFA), as well as spinopelvic parameters and the global sagittal spinal alignment from standing whole-lower-extremity and whole-spine radiographs preoperatively and at postoperative 2 weeks, 6 weeks, 6 months, 1 year, and 2 years. Linear mixed models were used to assess the relationships between KFC/KFA and between spinopelvic/global sagittal spinal alignments.

RESULTS

The KFC decreased abruptly immediately after TKA, and the correction was maintained for 2 years postoperatively. The KFA decreased gradually and approached the value of the KFC after 2 years. Of the spinopelvic parameters, sacral slope and pelvic incidence decreased significantly, in ways related to changes in KFA. There was no significant relationship between sagittal spinal alignment and postoperative changes in KFC.

CONCLUSION

Although the flexion contracture was corrected immediately after TKA, the standing KFA improved gradually over 2 years. The pelvic parameters showed compensatory changes according to the KFA. The decompensated sagittal spinal malalignment was not related to a relapse in flexion contracture.

Study of Patients with Bilateral Knee Osteoarthritis Undergoing Total Knee Replacement Procedure with Coexisting Lumbar Spondylosis Symptoms

Study Design

This is a prospective cohort study involving patients who were followed for 2 years after total knee replacement (TKR) to determine changes in lumbar spine and knee symptoms.

Purpose

The objectives of this study were to determine the percentage of patients undergoing bilateral TKR who present with coexisting lumbar spine problems and determine if TKR relieves lumbar spine symptoms.

Overview of Literature

No studies quantify the percentage of TKR patients who experience relief of lumbar spine symptoms after TKR surgery.

Methods

The study included 200 patients (164 females, 36 males) undergoing primary TKR. Follow-up was performed at 4 weeks, 3, 6, 12, and 24 months. Lumbar spine and knee symptom improvements were assessed using the Oswestry Disability Index (ODI) and Oxford Knee Score, respectively.

Results

All 200 patients undergoing bilateral TKR presented with radiographic lumbar spine degenerative pathology; 60% (n=120) of the patients presented with moderate to severe clinical symptoms of lumbar spondylosis, including 54% (n=108) with degenerative lumbar spondylosis and lumbar canal stenosis and 6% (n=12) with degenerative spondylolisthesis. Of the 120 patients who presented with lumbar spine problems, 90% (n=108) reported improvement in their symptoms; the ODI score improved from 42.5%±4.1% preoperative score to 15.6%±2.3% postoperative score (p-value<0.001). Of the 12 patients with no improvement, 10 patients underwent percutaneous procedures for their lumbar spine pathology with good results, one patient underwent surgery, and one declined any intervention.

Conclusions

A significant number of patients (60%) undergoing bilateral TKR also present with symptomatic lumbar spine problems. Patients with mild to moderate lumbar spine degenerative symptoms and no associated severe radiating pain on activity are more likely to experience relief of their symptoms post-TKR.

Periprosthetic Loss of Bone Mineral Density After Cementless Porous Tantalum and Cemented Total Knee Arthroplasties: A Mean of 11-Year Concise Follow-Up of a Previous Report

BACKGROUND

Our previous study showed that the decrease in relative change of bone mineral density (BMD) in the lateral part of the tibia was significantly less in the group treated with the cementless porous tantalum component than in the group treated with the cemented cobalt-chromium tibial component up to 5 years after the operation. However, the long-term benefits of porous tantalum tibial component on BMD have not been proven. The aim of this study was to update a matched cohort study at a minimum of 6 years' follow-up period.

METHODS

Twenty patients with a porous tantalum tibial component and 18 patients with a cemented cobalt-chromium-alloy tibial component were investigated for more than 6 years in the present study. The mean follow-up period was 11.4 years. Dual X-ray absorptiometry was used to measure the BMD.

RESULTS

The decrease in relative change of BMD in the lateral aspect of the tibia was significantly less with the porous tantalum tibial component than that with the cemented cobalt-chromium tibial component up to 5 years. However, at the final follow-up period, no significant difference was observed in the relative change of BMD between the 2 groups. No prosthetic migration or periprosthetic fracture was detected in either group.

CONCLUSION

The present study is one of the studies with the longest follow-up period on BMD after total knee arthroplasty. Porous tantalum tibial component did not have a favorable effect on the BMD of the proximal tibia after total knee arthroplasty for long term.

Contemporary Primary Total Knee Arthroplasty is Durable in Patients Diagnosed With Ankylosing Spondylitis

INTRODUCTION

Ankylosing spondylitis (AS) is a seronegative spondyloarthropathy affecting the axial spine and peripheral joints. Despite innovations in medical management, patients with AS experience two-fold the lifetime risk of total knee arthroplasty (TKA) compared to the general population. Moreover, recent data have indicated a correlation between spinal pathology and outcomes of TKAs.

METHODS

Our institutional total joint registry identified 19 patients (28 knees) with a diagnosis of AS treated with primary TKA from 2000 to 2016. The mean age at TKA was 68 years, and 84% of patients were men. The mean follow-up period was 6 years. Outcomes included implant survivorship, clinical outcomes, and complications.

RESULTS

Survivorship free from any revision was 88% at 10 years. A single patient required revision at 8 years for aseptic loosening. Survivorship free from any reoperation was 77% at 10 years. Reoperations included 2 manipulations under anesthesia and 1 superficial wound irrigation and debridement. Mean Knee Society score improved from 46 preoperatively to 89 postoperatively (P < .0001). The mean arc of motion improved from 108^o preoperatively to 116° postoperatively (P = .01). There were 6 complications that did not require reoperation.

CONCLUSION

Primary TKAs in patients with AS resulted in significant improvement in clinical outcomes with excellent 10-year implant survivorship. Although 2 manipulations under anesthesia were required, the range of motion was restored postoperatively. These data suggest that the contemporary primary TKA can achieve durable and reliable outcomes in patients with axial skeletal disease resulting from AS.

LEVEL OF EVIDENCE

IV.

Clinical and radiological features of lumbar degenerative spondylolisthesis who complicates osteoarthritis of the knee

BACKGROUND DATA

Correlation between lumbar degenerative disease and degenerative disorders of the knee joint have often been reported, however, detailed research concerning lumbar degenerative spondylolisthesis (DS) who complicates osteoarthritis of the knee (KOA) are scarce.

METHODS

A total of 184 consecutive surgically treated DS patients were identified, and divided into two groups: DS patients who complicate KOA (KOA group) and DS patients without KOA (non-KOA group). DS was defined as grade 1 or more, according to Meyerding's classification, and KOA was defined as grade 3 or more according to Kellgren-Lawrence classification. Clinical and the radiological differences of DS patients between KOA group and non-KOA group were investigated in order to clarify the features of DS patients who complicate KOA. Statistical significance using student's t-test and multivariate logistic regression analysis was performed to identify independent predictors of complicating KOA in DS.

RESULTS

KOA group and non-KOA group consisted of 57 and 127 patients, respectively, with both group predominantly of female patients. Clinical features of KOA group were significantly high in age and body mass index (BMI), and more likely to complicate circulatory system disorders than non-KOA group. Radiological features of KOA group were significantly high in frequency of double adjacent level spondylolisthesis, Pelvic incidence (PI), Pelvic tilt (PT), and PI-LL. Multivariate logistic regression analysis identified coexistence of circulatory system disorders (OR 2.251, p = 0.024) and PI-LL (OR 1.04, p < 0.001) to be an independent predictors of complicating KOA in DS patients.

CONCLUSIONS

Older age and overweighted female patients coexistence of circulatory system disorders, containing double adjacent level spondylolisthesis with high PI, PT, and PI-LL were the characteristics of DS patients who complicate KOA, particularly coexistence of circulatory system disorders and significantly high lumbo-pelvic sagittal mismatch were the most significant factors above all.

Influence of comorbid knee osteoarthritis on surgical outcome and sagittal spinopelvic/lower-extremity alignment in elderly patients with degenerative lumbar spondylolisthesis undergoing transforaminal lumbar interbody fusion

OBJECTIVE

This retrospective study aimed to clarify the influence of comorbid severe knee osteoarthritis (KOA) on surgical outcome in terms of sagittal spinopelvic/lower-extremity alignment in elderly patients with degenerative lumbar spondylolisthesis (DLS).

METHODS

In total, 110 patients aged at least 65 years (27 men, 83 women; mean age 74.0 years) who underwent short-segment lumbar fusion were included in the present study. Using the Kellgren-Lawrence (KL) grading system, patients were categorized into those with no to mild KOA (the mild-OA group: KL grades 0-2), moderate KOA (moderate-OA group: KL grade 3), or severe KOA (severe-OA group: KL grade 4). Surgical results were assessed using the Japanese Orthopaedic Association (JOA) scoring system, and spinopelvic/lower-extremity parameters were compared among the 3 groups. Adjacent-segment disease (ASD) was assessed over a mean follow-up period of 4.7 years (range 2-8.1 years).

RESULTS

The study cohort was split into the mild-OA group (42 patients), the moderate-OA group (28 patients), and the severe-OA group (40 patients). The severe-OA group contained significantly more women (p = 0.037) and patients with double-level listhesis (p = 0.012) compared with the other groups. No significant differences were found in mean postoperative JOA scores or recovery rate among the 3 groups. The mean postoperative JOA subscore for restriction of activities of daily living was only significantly lower in the severe-OA group compared with the other groups (p = 0.010). The severe-OA group exhibited significantly greater pelvic incidence, pelvic tilt, and knee flexion angle (KFA), along with a smaller degree of lumbar lordosis than the mild-OA group both pre- and postoperatively (all p < 0.05). Overall, the rate of radiographic ASD was observed to be higher in the severe-OA group than in the mild-OA group (p = 0.015). Patients with ASD in the severe-OA group exhibited significantly greater pelvic tilt, pre- and postoperatively, along with less lumbar lordosis, than the patients without ASD postoperatively (all p < 0.05).

CONCLUSIONS

A lack of lumbar lordosis caused by double-level listhesis and knee flexion contracture compensated for by far greater pelvic retroversion is experienced by elderly patients with DLS and severe KOA. Therefore, corrective lumbar surgery and knee arthroplasty may be considered to improve sagittal alignment, which may contribute to the prevention of ASD, resulting in favorable long-term surgical outcomes.

Comorbidities in Patients With End-Stage Knee OA: Prevalence and Effect on Physical Function

OBJECTIVE

To investigate the prevalence of comorbidities and their effect on physical function, quality of life (QOL), and pain, in patients with end-stage knee osteoarthritis (OA).

DESIGN

A cross-sectional study.

SETTING

A rehabilitation facility at university hospital.

PARTICIPANTS

Patients (N=577; 503 women and 74 men) diagnosed with end-stage knee OA between October 2013 and June 2018.

INTERVENTION

Not applicable.

MAIN OUTCOME MEASURES

Comorbidities were as follows: osteoporosis, presarcopenia, degenerative spine disease, diabetes, and hypertension. All patients completed the following performance-based physical function tests: stair-climbing test (SCT), 6-minute walk test (6MWT), timed Up and Go (TUG) test, and gait analysis. Self-reported physical function and pain were measured using Western Ontario McMaster Universities Osteoarthritis Index (WOMAC) and a visual analog scale (VAS), respectively, and self-reported QOL was measured using EuroQoL 5 dimensions (EQ-5D) questionnaire.

RESULTS

Univariate analyses revealed that patients with osteoporosis had significantly higher scores in SCT ascent, SCT descent, TUG, WOMAC pain tests, and lower scores in 6MWT, gait speed, and cadence tests than those without osteoporosis. Patients with presarcopenia recorded higher scores in SCT ascent, TUG, EQ-5D, and lower scores in 6MWT and gait speed tests than those without presarcopenia. Patients with degenerative spine disease showed higher scores in WOMAC pain and lower scores in gait speeds than those without degenerative spine disease. Patients with diabetes showed higher scores in SCT ascent than those without diabetes, and patients with hypertension showed lower scores in 6MWT than those without hypertension. After adjusting age, sex, and body mass index, SCT descent retained significant association with osteoporosis, SCT ascent showed independent association with presarcopenia and diabetes, and WOMAC pain revealed significant association with degenerative spine disease.

CONCLUSION

The results confirm associations between comorbidities, performance-based and self-reported physical functions, and QOL in patients with end-stage knee OA.

Comprehensive Analysis of Pain Management after Total Knee Arthroplasty

Total knee arthroplasty (TKA) has been much improved recently and it is regarded as one of the most common and successful surgical procedures that provides pain relief and improves function in patients with severe knee arthritis. However, recent studies have reported that 15%–20% of patients are not satisfied after TKA without evident clinical or radiological findings and the most common causes of patient dissatisfaction include residual pain and limited function. The evaluation and treatment of painful TKA relies on a thorough understanding of the origin by careful evaluation, and a systematic approach is essential to efficiently and effectively resolve the pain. Periarticular injections (PAIs) and nerve blocks are gaining popularity because they are associated with less side effects than systemic regimens. The analgesic efficacy and safety of PAI compared with nerve blocks for postoperative pain management still remain controversial. Therefore, more study is needed to determine if any changes in the regimen of the injection or technique could provide added benefit to long-term functional improvement beyond the perioperative period.

Outcome Assessment in Total Knee Arthroplasty: A Systematic Review and Critical Appraisal

BACKGROUND

The Outcome Measures in Rheumatology (OMERACT) initiative developed a core outcome set (COS) of domains to assess effectiveness of interventions for knee osteoarthritis. These domains (pain, physical function, patient global assessment, imaging at 1 year) should be assessed in every trial to make research evidence meaningful and comparable. We systematically evaluated and critically appraised the use of measurement instruments and outcome domains in prospective studies evaluating patients with knee osteoarthritis undergoing total knee arthroplasty (TKA) and assessed their accordance with the OMERACT COS.

METHODS

Literature search was performed until August 26, 2014, in Medline and Embase. Clinical trials and prospective observational studies with ≥50 participants and a follow-up of ≥1 year were included. We collected general study characteristics, comprehensive information on measurement instruments, and corresponding domains used.

RESULTS

This systematic review identified low accordance of used outcome domains with the OMERACT COS of domains published in 1997. Only 4 of 100 included studies included all recommended core domains. Pain (85% of studies) and physical function (86%) were assessed frequently, whereas patient global assessment (21%) and joint imaging (≥1 year; 27%) were rarely assessed. There was substantial heterogeneity in the use of measurement instruments (n = 111) investigating TKA.

CONCLUSION

More efforts are required to implement the existing COS. In addition, a more consistent use of adequate measurement instruments is important to make research evidence on TKA more relevant, better comparable, and thus more useful for guideline developers and clinical decision makers.

Concomitant low back pain impairs outcomes after primary total knee arthroplasty in patients over 65 years: a prospective, matched cohort study

INTRODUCTION

Knee osteoarthritis and low back pain (LBP) are two conditions with relatively high prevalence in patients over 65 years. The objective was to determine the effect of symptomatic LBP on the patient-reported outcome after primary TKA.

MATERIAL AND METHOD

A cohort of 48 patients with concomitant LBP was prospectively matched 1:2 with patients without LBP for gender, age, body mass index and preoperative knee function. LBP severity was measured with the Oswestry Disability Index (ODI). Patient-reported outcomes were assessed with reduced Short-Form (SF12), Western Ontario and McMaster Universities score (WOMAC), and visual analogue scale (VAS) for satisfaction. Functional outcome was assessed with the Knee Society Scores (KSS).

RESULTS

The mean postoperative follow-up was 3.2 years. At last follow-up, LBP cohort had significantly worse SF12, WOMAC, KSS and VAS scores than those patients without LBP. Preoperative ODI score was significantly correlated with outcomes.

CONCLUSION

Worse functional and patient-reported outcomes were obtained in patients over 65 years with concomitant LBP, and this was related to the intensity of preoperative LBP. Despite successful outcome in the knee, the LBP usually remains after TKA and this may impair satisfaction and patient-reported outcomes. These patients should be properly informed about their potential outcomes.

Spontaneous Improvement of Compensatory Knee Flexion After Surgical Correction of Mismatch Between Pelvic Incidence and Lumbar Lordosis

STUDY DESIGN

A retrospective study.

OBJECTIVE

The aim of this study was to investigate the correlation between pelvic incidence (PI) and lumbar lordosis (LL) mismatch and knee flexion during standing in patients with lumbar degenerative diseases and to examine the effects of surgical correction of the PI-LL mismatch on knee flexion.

SUMMARY OF BACKGROUND DATA

Only several studies focused on knee flexion as a compensatory mechanism of the PI-LL mismatch. Little information is currently available on the effects of lumbar correction on knee flexion in patients with the PI-LL mismatch.

METHODS

A group of patients with lumbar degenerative diseases were divided into PI-LL match group (PI-LL ≤ 10°) and PI-LL mismatch group (PI-LL > 10°). A series of radiographic parameters and knee flexion angle (KFA) were compared between the two groups. The PI-LL mismatch group was further subdivided into operative and nonoperative group. The changes in KFA with PI-LL were examined.

RESULTS

The PI-LL mismatch group exhibited significantly greater sagittal vertical axis (SVA), pelvic tilt (PT) and KFA, and smaller LL, thoracic kyphosis (TK), and sacral slope than the PI-LL match group. PI-LL, LL, PI, SVA, and PT were significantly correlated with KFA in the PI-LL mismatch group. From baseline to 6-month follow-up, all variables were significantly different in the operative group with the exception of PI, although there was no significant difference in any variable in the nonoperative group. The magnitude of surgical correction in the PI-LL mismatch was significantly correlated with the degree of spontaneous changes in KFA, PT, and TK.

CONCLUSION

The PI-LL mismatch would contribute to compensatory knee flexion during standing in patients with lumbar degenerative disease. Surgical correction of the PI-LL mismatch could lead to a spontaneous improvement of compensatory knee flexion. The degree of improvement in knee flexion depends in part on the amount of correction in the PI-LL mismatch.

LEVEL OF EVIDENCE

3.

Coexistent lumbar spine disorders have a crucial impact on the clinical outcome after total hip replacement

BACKGROUND

Degenerative hip and spine disease are known to frequently coexist. Lumbar spine disorders (LSDs), as opposed to other patient-related factors, are disregarded in the assessment of the clinical outcome after total hip replacement (THR). This prospective study investigates the influence of LSDs on the pre- and postoperative health-related quality of life and functional outcome of patients undergoing THR.

METHODS

According to clearly defined criteria, 42 patients scheduled for cementless THR were assigned either to the LSD (13 patients with LSDs) or non-LSD group (29 patients without LSDs). A clinical assessment was performed preoperatively as well as 12, 24 and 60 months postoperatively using the Harris hip score (HHS), the Western Ontario and McMaster University osteoarthritis index (WOMAC) and the 36-item short form health survey (SF-36).

RESULTS

The statistical analysis comparing the pre- and postoperative status within both groups showed an ongoing improvement of mean HHS and WOMAC after THR. The non-LSD group had a significantly higher postoperative HHS and WOMAC after 12, 24 and 60 months as well as SF-36 after 24 and 60 months. The LSD group improved significantly in the HHS at 24 and 60 months and the WOMAC at 12, 24 and 60 months postoperatively, whereas the SF-36 improvement was not significant. Comparison of preoperative data in both groups revealed a significantly higher SF-36 in the non-LSD group but no difference between the HHS and WOMAC. At each postoperative assessment, the HHS, WOMAC and SF-36, including its physical and mental health sum scores, were significantly higher in the non-LSD group, except for the WOMAC after 60 months.

CONCLUSION

Owing to their crucial impact on hip function scores and health-related quality of life, it is recommended to consider LSDs preoperatively in studies dealing with the clinical outcome after THR.