Clinical, patient-reported, radiographic and magnetic resonance imaging findings 11 years after acute posterior cruciate ligament injury treated non-surgically

BACKGROUND

Long-term consequences of posterior cruciate ligament (PCL) injury such as persistent posterior tibial translation and risk of osteoarthritis development are unclear. Additionally, little data is available describing the natural history of structural morphology of the ruptured PCL. The purpose of the study was to determine the long-term outcome after non-operatively treated PCL injury.

METHODS

Over 6-years, all acute knee injuries were documented by subacute MRI (median 8 days [5-15, 25th - 75th percentile] from injury to MRI). Twenty-six patients with acute PCL injury were identified of whom 18 (69%) participated in the long-term follow-up after 11 years. Follow-up included radiographic posterior tibial translation (RPTT) determined using the Puddu axial radiograph. weight-bearing knee radiographs, MRI and KOOS (Knee injury and Osteoarthritis Outcome Score).

RESULTS

On subacute MRI, 11 knees displayed total and 7 partial ruptures. At 11 (SD 1.9) years, the median RPTT was 3.7 mm (1.5-6.3, 25th - 75th percentile). Seven knees displayed radiographic osteoarthritis approximating Kellgren-Lawrence grade ≥ 2. All follow-up MRIs displayed continuity of the PCL. Patients with more severe RPTT (> 3.7 mm), had worse scores in the KOOS subscales for symptoms (mean difference 14.5, 95% CI 7-22), sport/recreation (30, 95% CI 0-65) and quality of life (25, 95% CI 13-57) than those with less severe RPTT (≤ 3.7 mm). This was also the case for the KOOS₄ (22, 95% CI 9-34).

CONCLUSION

Acute PCL injuries treated non-surgically display a high degree of PCL continuity on MR images 11 years after injury. However, there is a large variation of posterior tibial translation with higher values being associated with poorer patient-reported outcomes.

Factors associated with hand bone changes in early rheumatoid arthritis

BACKGROUND

The aim of this research was to assess if hand bone mineral density (HBMD) changes associated with the appearance of erosions in early rheumatoid arthritis (ERA), compared with the population-based control group. Additionally, we tried to identify if there are novel factors that associate with HBMD and erosive changes (EC), and if they are dissimilar. The study was conducted as the data are limited.

METHODS

The study group consisted of 83 ERA patients and 321 controls. Dual-Energy X-Ray Absorptiometry (DXA) machine was used to measure HBMD. EC of RA (rheumatoid arthritis) were assessed in X-rays of hands using Sharp scores. Life-style habits, inflammation markers were assessed to evaluate the effects of different factors.

RESULTS

The presence of ERA was associated with lower HBMD compared with controls (adjusted for age, gender, height and weight; b -0.01, p = 0.045). 76% (95% CI 65.3-84.6) of ERA patients had EC in hand X-ray. Smoking habits and higher BMI (body mass index) were associated with an increased likelihood of having RA specific EC. In ERA, decreasing of HBMD was associated with the elevation of interleukin-6 (IL-6) and rheumatoid factor (RF) positivity.

CONCLUSIONS

In ERA, HBMD changes were not associated with the appearance of erosions. Factors that associate in ERA with HBMD changes and appearance of erosions differ. HBMD assessment together with serum IL-6 level could be useful in everyday clinical practice for better surveillance of ERA patients who do not have EC in hand X-rays.

Are structural abnormalities on knee MRI associated with osteophyte development? Data from the Osteoarthritis Initiative

OBJECTIVE

To assess which structural abnormalities on knee MRI are associated with development of osteophytes in middle-aged subjects without radiographic knee osteoarthritis.

DESIGN

We included subjects from the Osteoarthritis Initiative, aged 40-55 years, Kellgren & Lawrence grade 0 in both knees, and knee MRIs from both knees available at baseline, 24, 48 and 72 months. Structural exposures on MRI assessed using MOAKS included cartilage damage, bone marrow lesions, meniscal tear, meniscal extrusion, and Hoffa/effusion synovitis. We assessed whether each structural exposure was associated with the development of osteophytes on MRI in the medial and lateral tibiofemoral, and patellofemoral compartment. We estimated hazard ratios (HR) including 95% confidence intervals (CI) for osteophyte development using a mixed complementary log-log regression model adjusted for age, sex, and body mass index.

RESULTS

We included 680 knees from 340 subjects with a mean (SD) age of 50 years (3.0), and 51% men. In the medial tibiofemoral compartment, the absolute risk of osteophyte development in the first 24-month period was 4% in knees without, and 15% in knees with medial meniscal tear. Corresponding adjusted HR was 6.6 (95%CI = 3.4-12.9). In the lateral tibiofemoral compartment, the adjusted HR for developing osteophytes having a lateral meniscal tear was 3.3 (95%CI = 1.3-8.4). In the patellofemoral compartment, patellofemoral cartilage damage was most clearly associated with developing osteophytes (HR = 2.6, 95%CI = 1.8-3.7).

CONCLUSIONS

Meniscal tear seem to be the strongest structural risk factor for the development of tibiofemoral osteophytes, and patellofemoral cartilage damage for the development of patellofemoral osteophytes, respectively. Local biomechanical factors are important in early osteophyte development.

Relationship Between Magnetic Resonance Imaging Features and Knee Pain Over Six Years in Knees Without Radiographic Osteoarthritis at Baseline

Objective

To explore whether magnetic resonance imaging (MRI) features suggestive of knee osteoarthritis (OA) are associated with presence of knee pain in possible early‐stage OA development.

Methods

We included 294 participants from the Osteoarthritis Initiative (mean ± SD age 50 ± 3 years; 50% women) with baseline Kellgren/Lawrence grade of 0 in both knees, all of whom had received knee MRIs at 4 different time points over 6 years (baseline, 24, 48, and 72 months). Using a linear mixed model (knees matched within individuals), we studied whether MRI features (meniscal body extrusion [in mm], cartilage area loss [score 0–39], cartilage full thickness loss [range 0–16], osteophytes [range 0–29], meniscal integrity [range 0–10], bone marrow lesions [BMLs] including bone marrow cysts [range 0–20], Hoffa‐ or effusion‐synovitis [absent/present], and popliteal cysts [absent/present]) were associated with knee‐specific pain as reported on the Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire using a 0–100 scale (worst to best).

Results

The differences in KOOS knee pain score for a knee with a 1 unit higher score on MRI were the following: meniscal extrusion –1.52 (95% confidence interval [95% CI] –2.35, –0.69); cartilage area loss –0.23 (95% CI –0.48, 0.02); cartilage full thickness loss –1.04 (95% CI –1.58, –0.50); osteophytes –0.32 (95% CI –0.61, –0.03); meniscal integrity –0.28 (95% CI –0.58, 0.02); BMLs including potential cysts –0.19 (95% CI –0.55, 0.16); synovitis 0.23 (95% CI –1.14, 1.60); and popliteal cysts 0.86 (95% CI –0.56, 2.29).

Conclusion

Meniscal extrusion, full thickness cartilage loss, and osteophytes are associated with having more knee pain. Although these features may be relevant targets for future trials, the clinical relevance of our findings is unclear because no feature was associated with a clinically important difference in knee pain.

Arthroscopic partial meniscectomy for a degenerative meniscus tear: a 5 year follow-up of the placebo-surgery controlled FIDELITY (Finnish Degenerative Meniscus Lesion Study) trial

Objectives

To assess the long-term effects of arthroscopic partial meniscectomy (APM) on the development of radiographic knee osteoarthritis, and on knee symptoms and function, at 5 years follow-up.

Design

Multicentre, randomised, participant- and outcome assessor-blinded, placebo-surgery controlled trial.

Setting

Orthopaedic departments in five public hospitals in Finland.

Participants

146 adults, mean age 52 years (range 35–65 years), with knee symptoms consistent with degenerative medial meniscus tear verified by MRI scan and arthroscopically, and no clinical signs of knee osteoarthritis were randomised.

Interventions

APM or placebo surgery (diagnostic knee arthroscopy).

Main outcome measures

We used two indices of radiographic knee osteoarthritis (increase in Kellgren and Lawrence grade ≥1, and increase in Osteoarthritis Research Society International (OARSI) atlas radiographic joint space narrowing and osteophyte sum score, respectively), and three validated patient-relevant measures of knee symptoms and function (Western Ontario Meniscal Evaluation Tool (WOMET), Lysholm, and knee pain after exercise using a numerical rating scale).

Results

There was a consistent, slightly greater risk for progression of radiographic knee osteoarthritis in the APM group as compared with the placebo surgery group (adjusted absolute risk difference in increase in Kellgren-Lawrence grade ≥1 of 13%, 95% CI −2% to 28%; adjusted absolute mean difference in OARSI sum score 0.7, 95% CI 0.1 to 1.3). There were no relevant between-group differences in the three patient-reported outcomes: adjusted absolute mean differences (APM vs placebo surgery), −1.7 (95% CI −7.7 to 4.3) in WOMET, −2.1 (95% CI −6.8 to 2.6) in Lysholm knee score, and −0.04 (95% CI −0.81 to 0.72) in knee pain after exercise, respectively. The corresponding adjusted absolute risk difference in the presence of mechanical symptoms was 18% (95% CI 5% to 31%); there were more symptoms reported in the APM group. All other secondary outcomes comparisons were similar.

Conclusions

APM was associated with a slightly increased risk of developing radiographic knee osteoarthritis and no concomitant benefit in patient-relevant outcomes, at 5 years after surgery.

Trial registration

ClinicalTrials.gov (NCT01052233 and NCT00549172).

A naturally aging knee, or development of early knee osteoarthritis?

AIM

To study the development of early knee osteoarthritis (OA) in subjects with and without risk factors for knee OA.

METHODS

We studied 340 subjects from the Osteoarthritis Initiative (OAI), aged 45-55 years (51% women), free of radiographic knee OA at baseline (n = 294 with and n = 46 without knee pain and other OA risk factors). At baseline, 24, 48, 72 and 96 months we compared the two groups for prevalence and overlap of knee OA as defined by magnetic resonance imaging (MRI-based OA), x-rays (Kellgren-Lawrence grade [KLG] ≥ 1), and pain, using a logistic mixed model. We studied the group differences (%) over time by subtracting the OA prevalence of those without risk factors from the group with risk factors.

RESULTS

The group with OA risk factors had higher proportions of MRI-based OA than the group without OA risk factors at all visits, but the difference diminished at 72 months (72 months difference = 11.9%, 95% confidence intervals [CI] = -2.3-26.1). Further, at 72 months, the presence of KLG ≥ 1 were similar in the two groups (-3.5%, 95% CI = -15.2-8.2). The proportion fulfilling all three OA definitions was 1.7% at 24 months and 4.8% at 72 months of those with OA risk factors and 0% and 2.2%, respectively, in those without.

CONCLUSION

Structural changes of the knee are common irrespective of the presence of pain or other OA risk factors. Such structural changes in absence of knee symptoms should probably be considered as risk factors for early OA rather than disease.

Structural abnormalities detected by knee magnetic resonance imaging are common in middle-aged subjects with and without risk factors for osteoarthritis

Background and purpose - Few data are available regarding structural changes present in knees without radiographically evident osteoarthritis (OA). We evaluated the prevalence of findings suggestive of knee OA by magnetic resonance imaging (MRI) in middle-aged subjects without radiographic OA with or without OA risk factors. Patients and methods - 340 subjects from the Osteoarthritis Initiative, aged 45-55 years (51% women) with Kellgren-Lawrence grade 0 in both knees, who had 3T knee MR images were eligible. 294 subjects had risk factors and 46 were without risk factors. MR images were assessed using the MOAKS scoring system. Results - At least 1 MR-detected feature was found in 96% (283/294) of subjects with risk factors and in 87% (40/46) of those without. Cartilage damage (82%), bone marrow lesions (60%), osteophytes (45%), meniscal body extrusion (32%), and synovitis-effusion (29%) were the most common findings in subjects with risk factors, while cartilage damage (67%), osteophytes (46%), meniscal body extrusion (37%), and bone marrow lesions (35%) were most common in subjects without. The prevalence of any abnormality was higher in subjects with OA risk factors than in subjects without (prevalence ratio adjusted for age and sex 1.3 [95% CI 1.1-1.6]), so was prevalence of subchondral cysts and bone marrow lesions. MR-detected structural changes were more frequent in patellofemoral joints. Interpretation - Our findings highlight the great challenge in distinguishing pathological features of early knee OA from what could be considered part of "normal ageing." Bone marrow lesions were more frequently found in subjects with multiple OA risk factors.

Natural History of Intrameniscal Signal Intensity on Knee MR Images: Six Years of Data from the Osteoarthritis Initiative

PURPOSE

To assess the natural history of intrameniscal signal intensity on magnetic resonance (MR) images of the medial compartment.

MATERIALS AND METHODS

Both knees of 269 participants (55% women, aged 45-55 years) in the Osteoarthritis Initiative without radiographic knee osteoarthritis (OA) and without medial meniscal tear at baseline were studied. One radiologist assessed 3-T MR images from baseline and 24-, 48-, and 72-month follow-up for intrameniscal signal intensity and tears. A complementary log-log model with random effect was used to evaluate the risk of medial meniscal tear, adjusting for age, sex, body mass index, and knee side.

RESULTS

At baseline, linear intrameniscal signal intensity in the medial compartment was present in 140 knees (26%). Once present, regression only in a single knee was observed. In 31 knees (19%) with linear intrameniscal signal intensity at any of the first three time points, the signal intensity progressed to a tear in the same segment, and in a single knee, the tear occurred in an adjacent segment. The corresponding number of tears without prior finding of intrameniscal signal intensities was 11 (3%). In the adjusted model, the hazard ratio for developing medial meniscal tear was 18.2 (95% confidence interval: 8.3, 39.8) if linear intrameniscal signal intensity was present, compared when there was no linear signal intensity. There was only one of 43 knees with injury reported in conjunction with the incident tear.

CONCLUSION

In middle-aged persons without OA, linear intrameniscal signal intensity on MR images is highly unlikely to resolve and should be considered a risk factor for medial degenerative meniscal tear.

Diagnostic and prognostic value of bone biomarkers in progressive knee osteoarthritis: a 6-year follow-up study in middle-aged subjects

OBJECTIVE

To determine the value of bone markers in early-stage progressive knee osteoarthritis (OA), a population-based cohort of middle-aged subjects with chronic knee complaints was followed over 6 years (two consecutive two 3-year periods).

METHODS

Tibiofemoral (TF) and patellofemoral (PF) radiographs were graded in 128 subjects (mean age at baseline 45 ± 6.2 years) in 2002, 2005 and 2008. Bone formation was assessed by the serum concentration of procollagen type I amino-terminal propeptide (sPINP); bone resorption by the level of the C-terminal cross-linked telopeptides of type I collagen (sCTx-I); and bone mineralization by the values of osteocalcin (sOC) by electrochemiluminescence immunoassay. A novel marker of bone resorption, urinary osteocalcin midfragments (uMidOC), was assayed using enzyme linked immunosorbent assay (ELISA).

RESULTS

Several diagnostic associations were found between the bone markers (PINP, OC, MidOC) and progressive OA expressed by TF osteophytosis. The increasing output of MidOC demonstrated several-fold higher risk for progressive TF osteophytosis [odds ratio (OR) 5.32; 95% confidence interval (CI) 1.41-20.06, P = 0.014] than other bone markers. The values of PINP had prognostic value for subsequent more severely expressed knee OA progression [r(s) = 0.460, P = 0.005].

CONCLUSIONS

Bone metabolism is activated in early-stage knee OA. OA progression was preceded by the enhanced bone formation (by PINP) and accompanied by the activation of bone formation (by PINP), non-collagenous bone resorption (by MidOC), as well as by changes in mineralization (by OC). All three bone markers had diagnostic value, and one of them, PINP, had also a predictive value for knee OA progression, especially for progressive osteophytosis.

The value of cartilage biomarkers in progressive knee osteoarthritis: cross-sectional and 6-year follow-up study in middle-aged subjects

To determine the possible diagnostic and prognostic value of cartilage biomarkers in early-stage progressive and nonprogressive knee osteoarthritis (OA) in a population-based cohort of middle-aged subjects with chronic knee pain. Design tibiofemoral (TF) and patellofemoral (PF) radiographs were graded in 128 subjects (mean age at baseline, 45 ± 6.2 years) in 2002, 2005, and 2008. Cartilage degradation was assessed by urinary C-telopeptide fragments of type II collagen (uCTx-II), synthesis by serum type II A procollagen N-terminal propeptide (sPIIANP), and articular tissue turnover in general by cartilage oligomeric matrix protein (sCOMP). Several diagnostic associations were found between all studied biomarkers and progressive osteophytosis. COMP and CTx-II had a predictive value for subsequent progressive osteophytosis in multiple knee compartments and in case of CTx-II-also for progressive JSN. Over the first 3 years (2002-2005), significant associations were observed between COMP and progressive osteophytosis, whereas 3 years later (2005-2008) between CTx-II and progressive JSN. Thus, the associations between cartilage markers (COMP, CTx-II) and progression of radiographic OA features--osteophytes and JSN--were different between 2002-2005 and 2005-2008. Logistic regression revealed that for every unit increase in COMP level, there was 33 % higher risk for TF osteophyte progression. During early-stage OA, the presence and progression of osteophytosis is accompanied by increased level of cartilage biomarkers. This is the first study to demonstrate biochemical differences over the course of knee OA, illustrating a phasic nonpersistent character of OA with periods of progression and stabilization.

Impact of cryopreservation on serum concentration of matrix metalloproteinases (MMP)-7, TIMP-1, vascular growth factors (VEGF) and VEGF-R2 in Biobank samples

BACKGROUND

Blood biomarkers are subject to pre-analytical variability. In many cases, the stability of important new tissue biomarkers during freeze cycles and storage has not been studied sufficiently.

METHODS

To test the stability of matrix metalloproteinases-7 (MMP-7) and their tissue inhibitors (TIMP-1), vascular growth factors (VEGF) and VEGF-receptor, serum samples were frozen and then thawed up to six times. The impact of storage temperature was investigated using an accelerated stability testing protocol. Stability at -20°C and -75°C was calculated using the Arrhenius equation.

RESULTS

The average concentration of TIMP-1 was stable, even after six freeze/thaw cycles. One thawing did not change the concentration of MMP-7 and VEGF-receptor. However, repeated freeze/thaw cycles increased the measured values significantly. Decreases in VEGF concentrations were dramatic, even after the first freeze/thaw cycle. According to the Arrhenius calculation, MMP-7 showed excellent stability, at least 5 years at -20°C and several 100 years at -75°C. The VEGF-receptor maintains 90% of its initial concentration at -20°C over 3 months, and decades at -75°C. TIMP-1 and VEGF showed poor stability with cryopreservation, even at -75°C.

CONCLUSIONS

The stability of MMP-7, TIMP-1, VEGF or VEGF-receptor in biobanking is highly variable, and this should be taken into account in the interpretation of results. A temperature -20°C is unsuitable for prolonged storage of the biomarkers investigated, and repeated thawing of sera is not recommended. VEGF is especially unstable and should be quantitated using serum that has never been frozen.

Association between ultrasonographic findings and bone/cartilage biomarkers in patients with early-stage knee osteoarthritis

Little is known regarding the association between ultrasonographic (US) findings and biomarkers of bone and cartilage in individuals with knee osteoarthritis (OA). We investigated (1) US findings in early-stage knee OA and (2) the association between US findings and bone/cartilage biomarkers. A population cohort aged 35-55 years (n = 106) with early-stage knee OA was investigated. US examination was performed according to European League against Rheumatism (EULAR) guidelines using a 7.5-MHz probe. Biomarkers of bone resorption (CTx-I) and formation (PINP), cartilage resorption (U-CTx-II) and synthesis (S-PIIANP), and general bone and cartilage biomarkers (OC, COMP) were assessed. The most prevalent US findings were tendon calcification, synovial thickening, and suprapatellar effusion. In women, the presence of tendon calcification and Baker's cysts could predict 36% of the variability in U-CTx-II levels. The presence of osteophytes and tendon calcification predicted up to 38% of the variability of PIIANP concentration. Defects in subchondral bone, meniscal changes, and effusion predicted up to 29% of the variability in COMP levels. Tendon calcification was related to cartilage synthesis (based on PIIANP levels) in men and to cartilage degradation (based on U-CTx-II concentrations) in women. US signs of synovitis were reflected metabolically by markers of joint tissue metabolism. Tendon calcification, synovial thickening, and effusion were common US findings in early-stage knee OA. US-detectable findings were substantially responsible for the variability in bone and cartilage biomarkers, associations reflective of the active metabolism of soft tissues in early-stage OA.

Urinary osteocalcin and other markers of bone metabolism: the effect of risedronate therapy

OBJECTIVE

Serum osteocalcin (S-OC) is widely used as an index of bone formation. However, there is evidence that some urinary fragments of OC reflect resorption and might be useful in monitoring antiresorptive therapy. Here, we report 6-month changes in urinary midfragments of osteocalcin (U-MidOC) and other bone turnover markers in response to risedronate treatment.

MATERIAL AND METHODS

The study group comprised 19 patients with postmenopausal osteoporosis, aged 49-66 years, and receiving risedronate therapy. Fifty-four premenopausal women served as controls. Osteoporosis was diagnosed by lumbal bone mineral density (BMD). Urinary osteocalcin was measured by the U-MidOC assay for midfragments. Bone formation was assessed by S-PINP and S-OC, and resorption by S-CTx-I.

RESULTS

At baseline, U-MidOC was significantly correlated only with S-OC. After the 1st month of therapy, a similar decrease was observed in the values of U-MidOC and S-CTx-I, but in formation markers S-P1NP and S-OC only after three months. The rapid decrease in U-MidOC, analogous to S-CTX-I, and the different kinetics for urinary and serum OC suggest that urinary OC midfragments are more associated with resorption than S-OC. An association was also observed between the 1-month change in U-MidOC and 12-month gain in lumbar BMD. The response in U-MidOC after only the 1st month of therapy makes it a potential marker for monitoring the effect of risedronate, presumably reflecting different aspects of bone resorption than S-CTx-I does.

Monte Carlo Markov chain methods for genome screening

We used Monte Carlo Markov chain (MCMC) methods to analyze a quantitative trait, MAO level, and a discrete trait, Collaborative Study on the Genetics of Alcoholism (COGA) alcoholism. Segregation, linkage, and haplotype sharing were analyzed and effects of marker map features were examined. For MAO, modest signals were found on chromosomes 1 and 17 for raw data, and 15 for covariate-adjusted data. For alcoholism, a strong signal was found on chromosome 1 with modest signals on chromosomes 4 and 10.

Gene-culture coevolution and sex ratios: II. Sex-chromosomal distorters and cultural preferences for offspring sex

Cultural preferences for the sex of offspring may produce behavior, such as female infanticide, sex-selective abortion and sex-selective parental investment, which alter the sex ratio in a population. Empirical evidence suggests that some genetic sex-ratio distorters are located on the sex chromosomes. Interactions between cultural preferences and sex-linked sex-ratio distorters are examined. Criteria for the spread of cultural preferences and sex-chromosomal distorter alleles are derived analytically, and the coevolution of preferences and distorters is examined through numerical iteration. Evolutionary equilibria and trajectories of gene-culture interactions involving sex-chromosomal distorter alleles may produce severely male- or female-biased primary sex ratios and adult sex ratios in populations. Adult sex ratios, primary sex ratios, allele frequencies and the prevalence of cultural preferences in the population are sensitive to initial conditions and cultural transmission parameters. During the coevolutionary process phenoallelic association is observed in many cases and is associated with unusual dynamics.

A gene-culture model of human handedness

A model of handedness incorporating both genetic and cultural processes is proposed, based on an evolutionary analysis, and maximum-likelihood estimates of its parameters are generated. This model has the characteristics that (i) no genetic variation underlies variation in handedness, and (ii) variation in handedness among humans is the result of a combination of cultural and developmental factors, but (iii) a genetic influence remains since handedness is a facultative trait. The model fits the data from 17 studies of handedness in families and 14 studies of handedness in monozygotic and dizygotic twins. This model has the additional advantages that it can explain why monozygotic and dizygotic twins and siblings have similar concordance rates, and no hypothetical selection regimes are required to explain the persistence of left handedness.

Gene-culture coevolution and sex ratios: the effects of infanticide, sex-selective abortion, sex selection, and sex-biased parental investment on the evolution of sex ratios

The evolutionary consequences of culturally transmitted practices that cause differential mortality between the sexes, thereby distorting the sex ratio (e.g., female infanticide and sex-selective abortion), are explored using dynamic models of gene-culture coevolution. We investigate how a preference for the sex of offspring may affect the selection of genes distorting the primary sex ratio. Sex-dependent differences in mortality have been predicted to select for a male- or female-biased primary sex ratio, to have no effect, or to favor either under different circumstances. We find that when a mating pair's behavior modifies mortality rates in favor of one sex, but does not change the number of offspring produced in the mating, the primary sex ratio will evolve a bias against the favored sex. However, when the total number of offspring of a mating pair is significantly reduced as a consequence of their prejudice, the primary sex ratio will evolve to favor the preferred sex. These results hold irrespective of whether the sex ratio is distorted by the mother's, the father's or the individual's own autosomal genes. The use of dynamic models of gene-culture coevolution allows us to explore the evolution of alleles which distort the sex ratio, as well as the final equilibrium states of the system. Gene-culture interactions can provide equilibria different from those in purely genetic systems, slow the approach to these equilibria by orders of magnitude, and move the primary (PSR) and the adult sex ratio (ASR) away from any stable equilibrium for hundreds of generations.