The musculoskeletal effects of smoking

The effect of cannabinoids on single-level lumbar arthrodesis outcomes in a rat model

BACKGROUND CONTEXT

The opioid epidemic is a public health crisis affecting spine care and pain management. Medical marijuana is a potential nonopioid analgesic yet to be studied in the surgical setting since its effects on bone healing are not fully understood. Studies have demonstrated analgesic and potentially osteoinductive properties of cannabinoids with endocannabinoid receptor expression in bone tissue.

PURPOSE

We hypothesize that tetrahydrocannabinol (THC) and cannabidiol (CBD) will not decrease bone healing in spinal fusion.

STUDY DESIGN

Seventy-eight adult Sprague-Dawley rats were used for this study. Utilizing allogenic bone grafts (6 donor rats), posterolateral inter-transverse lumbar fusion at the L4-L5 level was performed. The animals were equally divided into four treatment groups, each receiving 0.1 ml intraperitoneal injections weekly as follows: placebo (saline), 5 mg/kg THC, 5 mg/kg CBD, and a combination of 5 mg/kg THC and 5mg/kg CBD (Combo).

METHODS

Callus tissue was harvested 2- and 8-weeks postsurgery for qPCR assessment to quantify changes in the expression of osteogenic genes. Manual palpation was done to assess the strength of the L4-L5 arthrodesis on all rats. μCT image-based callus analysis and histology were performed. One-way ANOVA followed by post hoc comparisons was performed.

RESULTS

μCT demonstrated no significant differences. Treatment groups had slightly increased bone volume and density compared to control. qPCR at 2 weeks indicated downregulated RANKL/OPG ratios skewing towards osteogenesis in the CBD group, with the THC and CBD+THC groups demonstrating a downward trend (p>.05). ALPL, BMP4, and SOST were significantly higher in the CBD group, with CTNNB1 and RUNX2 also showing an upregulating trend. The CBD group showed elevation in Col1A1 and MMP13. Data at eight weeks showed ALPL, RUNX2, BMP4, and SOST were downregulated for all treatment groups. In the CBD+THC group, RANK, RANKL, and OPG were downregulated. OPG downregulation reached significance for the THC and CBD+THC group compared to saline. Interestingly, the RANKL/OPG ratio showed upregulation in the CBD and CBD+THC groups. RANKL showed upregulation in the CBD group. At 2 and 8 weeks, the CBD treatment group showed superior histological progression, increasing between time points.

CONCLUSION

This study demonstrates that CBD and THC have no adverse effect on bone healing and the rate of spinal fusion in rats. Osteogenic factors were upregulated in the CBD-treated groups at 2 weeks, which indicates a potential for bone regeneration. In this group, compared to control, the RANKL/OPG ratio at the early healing phase demonstrates the inhibition of osteoclast differentiation, enhancing bone formation. Interestingly, it shows promoted osteoclast differentiation at the later healing phase, enhancing bone remodeling. This aligns with the physiological expectation of a lower ratio in the early phases and a higher ratio in the later remodeling phases.

CLINICAL SIGNIFICANCE

CBD and THC showed no inhibitory effects on bone healing in a spinal fusion model. Moreover, histologic and gene expression analysis demonstrated that CBD may, in fact, enhance bone healing. Further research is needed to confirm the safe usage of THC and CBD in the postoperative setting following spinal fusions.

Effect of tobacco usage on surgical site wound problems after primary total hip and total knee arthroplasty: A meta-analysis

The meta-analysis aims to assess and compare the effect of tobacco usage on surgical site wound problems (SSWPs) after primary total hip and total knee arthroplasty (PTH&TKA). Using dichotomous random- or fixed-effects models, the outcomes of this meta-analysis were examined, and the odds ratio (OR) with 95% confidence intervals (CIs) was computed. Fifteen studies from 2001 to 2023 were enrolled for the present meta-analysis including 560 819 personals with PTH&TKA. Smokers had significantly higher SSWPs (OR, 1.53; 95% CI, 1.21-1.94, p < 0.001) compared with non-smokers in personals with PTH&TKA. Current smokers had significantly higher SSWPs (OR, 1.59; 95% CI, 1.40-1.80, p < 0.001) compared with non-smokers in personals with PTH&TKA. Current smokers had significantly higher SSWPs (OR, 1.42; 95% CI, 1.19-1.70, p < 0.001) compared with former smokers in personals with PTH&TKA. However, former smokers and non-smokers had no significant difference in SSWPs (OR, 1.11; 95% CI, 0.95-1.30, p = 19) in personals with PTH&TKA. The examined data revealed that in personals with PTH&TKA smokers had significantly higher SSWPs compared with non-smokers, and current smokers had significantly higher SSWPs compared with non-smokers and former smokers; however, former smokers and non-smokers had no significant difference in SSWPs. Yet, attention should be implemented while relating to its values since some of the comparisons were made using a low number of selected studies.

Scaphoid nonunion: a novel modification of Matti-Russe technique with enhanced recovery and full clinical and radiographic union

BACKGROUND

A scaphoid fracture is a common injury affecting the wrist joint. A fracture of the carpus scaphoid can heal uneventfully or be complicated by non-union. Scaphoid non-union can result in persistent wrist pain, and with functional difficulties affecting all activities of daily living of the patients, this disability is expected to be significant since most of these patients are young active adults.

HYPOTHESIS

Extensive removal of the bone from the scaphoid, with the application of a large amount of cancellous bone graft and fixation with two to three wires, could lead to a high union rate and a good functional outcome.

METHODS

Eighteen patients with scaphoid fracture non-union were recruited during their visit to the upper limb clinic at our institute. Demographic data were collected, and data regarding comorbidities, smoking, manual work, and others were recorded. Data regarding the interval between injury and surgery, time to radiographic union, and functional wrist scores were reported as well.

RESULTS

A cohort of 18 patients was included. The mean age of patients was 30 years; most of our patients were healthy (83.3%), and more than two-thirds were smokers (72.2%). The mean follow-up time was 18 months (1.5 years), 15 patients (83.3%) achieved radiographic unions by 2-3 months, and the remaining 3 patients (16.7%) achieved radiographic unions by (4-5) months, i.e., all patients achieved successful radiographic unions by 5 months at maximum. The mean Mayo score for our series was 83.6 (± 12.4), with 5 patients (27%) achieved ≥ 95% which indicates a significantly high functioning wrist in our cohort.

CONCLUSION

Our modified technique with enhanced stability from using three k-wires can achieve full clinical and radiographic unions and result in enhanced recovery postoperatively with cast immobilization limited to 6 weeks total.

LEVEL OF EVIDENCE

IV Case series study.

Factors influencing choice of treatment for proximal humeral fractures elaborated in a Delphi consensus process

INTRODUCTION

Hitherto, the decision-making process for treatment of proximal humerus fractures (PHF) remains controversial, with no established or commonly used treatment regimens. Identifying fracture- and patient-related factors that influence treatment decisions is crucial for the development of such treatment algorithms. The objective of this study was to define a Delphi consensus of clinically relevant fracture- and patient-related factors of PHF for clinical application and scientific research.

METHODS

An online survey was conducted among an international panel of preselected experienced shoulder surgeons. An evidence-based list of fracture-related and patient-related factors affecting treatment outcome after PHF was generated and reviewed by the members of the committee through online surveys. The proposed factors were revised for definitions, and suggestions from the first round mentioned in the free text were included as possible factors in the second round of surveys. Consensus was defined as having at least a two-thirds majority agreement.

RESULTS

The Delphi consensus panel consisted of 18 shoulder surgeons who completed 2 rounds of online surveys. There was an agreement of more than two-thirds of the panel for three fracture-related factors affecting treatment decision in the case of PHF: head-split fracture, dislocated tuberosities, and fracture dislocation. Of all patient-related factors, a two-thirds consensus was reached for two factors: age and rotator cuff tear arthropathy.

CONCLUSION

This study successfully conducted a Delphi consensus on factors influencing decision-making in the treatment of proximal humeral fractures. The documented factors will be useful for clinical evaluation and scientific validation in future studies.

Incidence, Microbiological Studies, and Factors Associated With Prosthetic Joint Infection After Total Knee Arthroplasty

Importance

Despite the frequency of total knee arthroplasty (TKA) and clinical implications of prosthetic joint infections (PJIs), knowledge gaps remain concerning the incidence, microbiological study results, and factors associated with these infections.

Objectives

To identify the incidence rates, organisms isolated from microbiological studies, and patient and surgical factors of PJI occurring early, delayed, and late after primary TKA.

Design, Setting, and Participants

This cohort study obtained data from the US Department of Veterans Affairs (VA) Corporate Data Warehouse on patients who underwent elective primary TKA in the VA system between October 1, 1999, and September 30, 2019, and had at least 1 year of care in the VA prior to TKA. Patients who met these criteria were included in the overall cohort, and patients with linked Veterans Affairs Surgical Quality Improvement Program (VASQIP) data composed the VASQIP cohort. Data were analyzed between December 9, 2021, and September 18, 2023.

Exposures

Primary TKA as well as demographic, clinical, and perioperative factors.

Main Outcomes and Measures

Incident hospitalization with early, delayed, or late PJI. Incidence rate (events per 10 000 person-months) was measured in 3 postoperative periods: early (≤3 months), delayed (between >3 and ≤12 months), and late (>12 months). Unadjusted Poisson regression was used to estimate incidence rate ratios (IRRs) with 95% CIs of early and delayed PJI compared with late PJI. The frequency of organisms isolated from synovial or operative tissue culture results of PJIs during each postoperative period was identified. A piecewise exponential parametric survival model was used to estimate IRRs with 95% CIs associated with demographic and clinical factors in each postoperative period.

Results

The 79 367 patients (median (IQR) age of 65 (60-71) years) in the overall cohort who underwent primary TKA included 75 274 males (94.8%). A total of 1599 PJIs (2.0%) were identified. The incidence rate of PJI was higher in the early (26.8 [95% CI, 24.8-29.0] events per 10 000 person-months; IRR, 20.7 [95% CI, 18.5-23.1]) and delayed periods (5.4 [95% CI, 4.9-6.0] events per 10 000 person-months; IRR, 4.2 [95% CI, 3.7-4.8]) vs the late postoperative period (1.3 events per 10 000 person-months). Staphylococcus aureus was the most common organism isolated overall (489 [33.2%]); however, gram-negative infections were isolated in 15.4% (86) of early PJIs. In multivariable analyses, hepatitis C virus infection, peripheral artery disease, and autoimmune inflammatory arthritis were associated with PJI across all postoperative periods. Diabetes, chronic kidney disease, and obesity (body mass index of ≥30) were not associated factors. Other period-specific factors were identified.

Conclusions and Relevance

This cohort study found that incidence rates of PJIs were higher in the early and delayed vs late post-TKA period; there were differences in microbiological cultures and factors associated with each postoperative period. These findings have implications for postoperative antibiotic use, stratification of PJI risk according to postoperative time, and PJI risk factor modification.

Smoking induces increased apoptosis in osteoblasts: changes in bone matrix organic components

Clinical studies demonstrate the impact of smoking on bone tissue fragility and higher incidence of fractures. However, it is not totally understood which physiological mechanisms could be involved in these events. Previously, we showed important changes in bone tissue components in experimental model of cigarette smoke (CS) exposure. CS exposure induces worsening in bone mineralization and a decrease in collagen type I deposition, leading to bone fragility. Considering that the majority of clinical studies described bone structural changes by radiographic images, in this study we performed analyses "in situ" using tissue samples from smokers, former smokers and non-smokers to better understand how the increase in inflammatory mediators induced by smoking exposure could interfere in bone cells activity leading bone structural changes. We observed increased levels of IL-1β, IL-6 and TNF-α in bone tissue homogenates with a concomitant increase in osteoblast apoptosis in smokers and former smokers compared with non-smokers. Histological changes in both smokers and former smokers were characterized by reduction in collagen type I. Only in smokers, it was observed decrease in trabecular area, suggesting increased bone resorption and increase in collagen type V. These results showed that osteoblasts apoptosis in association with increased bone resorption leads bone structural changes in smokers.

The Impact of Smoking on Delayed Osseous Union After Arthrodesis Procedures in the Hand and Wrist

PURPOSE

The purpose of this study was to evaluate the relationship between smoking and delayed radiographic union after hand and wrist arthrodesis procedures. We hypothesized that smoking would be associated with a higher rate of delayed union.

METHODS

All cases of hand or wrist arthrodesis procedures in patients aged ≥18 years from 2006 to 2020 were identified. Cases were included if they had >90 days of radiographic follow-up or evidence of union before 90 days. Baseline demographics were recorded for each case including smoking status at the time of surgery. Complications were recorded and all postoperative radiographs were reviewed to assess for evidence of delayed union (defined as lack of osseous union by 90 days after surgery). We compared active smokers and nonsmokers and performed a logistic regression analysis to estimate the odds of experiencing a delayed radiographic union.

RESULTS

A total of 309 arthrodesis cases were included and 24% were active smokers. Overall, radiographic evidence of a delayed union was found in 17% of cases. Smokers were significantly more likely to have a delayed union compared with nonsmokers (27% vs 14%). Results of the adjusted logistic regression analysis demonstrated that there was a significantly increased odds of experiencing a delayed union for patients who were active smokers compared with nonsmokers (odds ratio, 2.20; 95% confidence interval, 1.09-4.43). In addition, the rate of symptomatic nonunion requiring reoperation was higher in smokers (15%) compared with nonsmokers (6%).

CONCLUSIONS

Smoking was associated with increased odds of delayed radiographic union in patients undergoing hand and wrist arthrodesis procedures. Patients should be counseled appropriately on the risks of smoking on bone healing and encouraged to abstain from nicotine use in the perioperative period.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic II.

What Is the Fate of Total Joint Arthroplasty Patients Who Are Asked to Quit Smoking Prior to Surgery?

Background

Smoking is a known risk factor for complications following primary total joint arthroplasty (TJA). Little is known regarding the fate of patients who are asked to quit smoking before surgery. The purpose of this study was to evaluate the success of smoking cessation prior to primary TJA and the impact of smoking cessation on perioperative outcomes.

Methods

This is a retrospective review of patients who presented between 2008 and 2020 to a single academic medical center with a documented smoking history and were asked to quit smoking prior to receiving a date for primary TJA. The cohort was surveyed about smoking cessation, smoking history, use of quit aids, seeking surgery elsewhere due to the cessation policy, and postoperative complications. Descriptive statistics evaluated the relationship between demographics, smoking cessation, and postoperative complications.

Results

A total of 101 patients completed the survey with an overall response rate of 48%. Sixty-two percent of patients quit smoking before surgery, and 51% of these patients reported remaining smoke-free at 6 months postoperatively. The average time to quit before TJA was 45 days (range: 1-365 days), and 62% quit without quit aids. The wound complication/infection rate was significantly higher for patients who did not stop smoking prior to TJA (4 of 16; 27%) than for those who did quit prior to surgery (3 of 63; 5%; P = .02).

Conclusions

This study demonstrates that most patients (62%) will stop smoking, if required, prior to primary TJA. Furthermore, 51% of patients reported abstinence from smoking at 6 months following TJA. TJA appears to be an effective motivator for smoking cessation.

Level of Evidence

III (retrospective cohort study).

Symptomatic Hammertoes Treatment Comparison: Peg-in-Hole Arthrodesis Versus End-to-End Screw Fixation

Proximal interphalangeal (PIP) arthrodesis technique utilizing the peg-in-hole arthrodesis was founded to avoid the use of retained internal fixation implants and thereby potentially decrease the concern of hardware complication. The specific aim of this study was to report the complication rates of the modified peg-in-hole arthrodesis technique and the end-to-end arthrodesis with single screw fixation technique for correcting symptomatic hammertoe deformities in lesser digits. This retrospective chart review included patients who underwent surgical hammertoe correction of lesser digits between the dates of January 2012 and December 2019. Patient demographic data and charts were reviewed to evaluate need for revision including screw/pin removal and complications related to corrective surgery. Five hundred ninety-three symptomatic hammertoe deformity cases (443 female, 150 male) were identified, with 113 cases (88 female, 25 male) treated with peg-in-hole arthrodesis technique and 480 cases (355 female, 125 male) treated with end-to-end arthrodesis with a single screw technique. The deformity recurrence rate was not significantly different between the two techniques (peg-in-hole: 10%, end-to-end: 13%, p = .428). There were 97 cases with postoperative complications that required re-operation (peg-in-hole: 7 cases, end-to-end: 90 cases) with the majority detected at <6 months. There was no statistically significant difference in reoperation rate between the peg-in-hole technique and the end-to-end arthrodesis technique reoperated with reasons excluding simple screw removal (p = .068). This study tended to show these two arthrodesis techniques have equivalent risks and similar success in bone healing; however, the peg-in-hole arthrodesis technique offers an advantage that does not result in retained hardware.

The Influence of Smoking on Healing of Scaphoid Non-union after a Vascularized Pedicle Bone Flap Operation: A Review and Meta-analysis

BACKGROUND

The purpose of this study is to compare the vascularized bone flaps (VBF) that are used in operations for scaphoid non-union in smokers and non-smokers and to scrutinize if the better biological potential of the VBFs can counteract the negative influence of smoking on healing.

MATERIALS AND METHODS

Our study included articles published until 2016, with scaphoid non-union patients who were operated on with a VBF or a VBG.

RESULTS

Eighteen articles met eligibility criteria with 335 non-smokers and 136 smokers totally. Healing of the scaphoid non-union was significantly more probable in the non-smoking group (OR=5.54, p<0.001). Patients with avascular necrosis in the proximal pole of the scaphoid (AVNPP) and non-AVNPP showed that non-smoking favors a better healing rate in both of these subgroups (p<0.001 and p<0.001, respectively). Non-smokers have 11 times and the non-AVNPP patient's 7.7 times greater probability of healing of the non-union. Meta-analysis of the data for time for healing showed a longer time in the smokers' group by 2.46 weeks, though non-statistically significant. The analysis could not prove that smoking is a predisposing factor for the development of AVNPP (spearman=0.094, p<0.05). Despite that, preoperative smoking cessation proved to be an inadequate healing moderator (OR=3.5, p=0.268). Finally, VBFs showed a significantly better healing rate compared with nVBGs in smokers (p=0.001).

CONCLUSIONS

A hand surgeon should always take into consideration that smoking negatively influences the healing potential of a scaphoid non-union despite the theoretically superior biological background that VBFs offer. In patients who refuse to quit smoking, a VBF may be considered a better choice than a conventional graft.

A 10-Year Follow-Up of Ankle Syndesmotic Injuries: Prospective Comparison of Knotless Suture-Button Fixation and Syndesmotic Screw Fixation

Background: Acute syndesmosis injury (ASI) is an indication for surgical stabilization if instability is confirmed. In recent years, fixation using the knotless suture-button (SB) device has become increasingly established as an alternative to set screw fixation (SF). This study directly compared the clinical long-term results after prospective randomized inclusion. Materials and Methods: Between 2011 and 2012, 62 patients with ASI were enrolled in a prospective, randomized, and monocentric study. Forty-one patients were available for a 10-year follow-up ((31 males and 10 females), including 21 treated with SB (mean age 44.4 years), and 20 with SF (mean age 47.2 years)). In addition to comparing the demographic data and syndesmosis injury etiology, follow-up assessed the Olerud−Molander Ankle Score (OMAS) and FADI-Score (Foot and Ankle Disability Index Score) with subscales for activities of daily living (ADL) and sports activity. Results: The mean OMAS was 95.98 points (SB: 98.81, SF: 93.00), the mean FADI ADL was 97.58 points (SB: 99.22, SF: 95.86), and the mean FADI Sport was 94.14 points (SB: 97.03, SF: 91.10). None of the measurements differed significantly between the groups (p > 0.05). No clinical suspicion of chronic instability remained in any of the patients, regardless of treatment. Conclusions: The short-term results showed that athletes in particular benefit from SB fixation due to their significantly faster return to sports activities. However, the available long-term results confirm a very good outcome in the clinical scores for both approaches. Chronic syndesmotic insufficiency was not suspected in any of the patients. Level of evidence: I, randomized controlled trial.

Effect of Smoking on the Healing of Tibial Shaft Fractures in a Rural Indian Population

Background

Tibial shaft fractures account for 17% of all lower limb fractures. Nonunion and infection rates are estimated to be between 2% and 10%. Bone healing is a complex process that is influenced by biological, mechanical, and systemic factors. Adverse smoking effects on cardiovascular and respiratory systems have been well documented. An increasing interest in the effect of smoking on fracture healing following trauma has been noted in recent years. The biological consequence of smoking is relevant, especially in trauma surgery where no way of preventing presurgical smoking has been noted, hence increasing the patient’s risk of nonunion. Cigarette smoking has been shown to impair fracture union and wound healing and lead to an increased risk of fracture site infection. Smoking and high-energy trauma are considered important risk factors for the delayed union of tibial shaft fractures.

Objectives

This study aims to assess the adverse effects of smoking in patients with tibial shaft fractures following trauma and fracture fixation.

Materials and methods

A retrospective cohort study was done on 110 (55 smokers and 55 nonsmokers) patients treated with intramedullary nailing or plating for tibial shaft fractures between July 2017 and January 2021 in the hospital of the current study. Fracture healing was assessed at the end of months 1, 3, and 6 and year 1.

Results

The mean time of healing in smokers was >48 weeks, whereas the average time to union was 24 weeks in nonsmokers. The majority (54.6%) of smokers took >48 weeks to heal, whereas 81.8% of patients in the nonsmoking group took 24-28 weeks to heal.

Conclusion

Similar to the results obtained in previous studies, our study showed that smoking hinders fracture healing after surgical fixation, and smokers have a higher chance of developing surgical site infection and osteomyelitis. Smokers take a longer time for radiological union and also have a high chance of delayed union and nonunion when compared with nonsmokers, which was shown in our study and is consistent with the results obtained in previous studies. Postoperative smoking cessation is as important as preoperative smoking cessation, and patients should be strictly counseled regarding the same.

Tobacco smoking is associated with more pain and worse functional outcomes after torsional ankle fracture

OBJECTIVE

The purpose of this study was to assess the impact of current and remote tobacco smoking on clinical and functional outcomes after torsional ankle fracture.

METHODS

Nine hundred thirty-five patients treated surgically for torsional ankle fracture over 9 years were reviewed. Tobacco smoking status at the time of injury was defined as current (48.3%), former (11.7%), and nonsmoker (40.0%). Complications, unplanned secondary procedures, pain medication use, and functional outcome scores, as measured by Foot Function Index and Short Musculoskeletal Function Assessment (SMFA) surveys.

RESULTS

Mean age was 44.8 years, with 50.3% male. More than 6 months following injury current smokers were more likely than former smokers and nonsmokers to report ankle pain (67.8% vs 45.8% vs 47.5%) and to use prescription pain medicines (23.0% vs 10.4% vs 6.3%), all P < .05. Multiple logistic regression found current tobacco use to be an independent predictor for prescription pain medication use, and worse scores for the Foot Function Index, SMFA Dysfunction, and SMFA Bothersome scores, all P < .05. Complications occurred in 15.5% of all patients, and 10.7% underwent unplanned secondary operations. Tobacco smoking was not associated with more complications or secondary procedures.

CONCLUSION

Current smokers are more likely to use prescription pain medications several months after injury and have worse patient-reported functional outcome scores after surgical treatment of torsional ankle fractures than former smokers and nonsmokers.

Smoking Is Associated With Lower Satisfaction in Nondiabetic Patients Undergoing Minimally Invasive Single-level Transforaminal Lumbar Interbody Fusion

STUDY DESIGN

This was a retrospective review of prospectively collected registry data.

OBJECTIVE

The objective of this study was to investigate the effect of smoking on 2 years postoperative functional outcomes, satisfaction, and radiologic fusion in nondiabetic patients undergoing minimally invasive transforaminal lumbar interbody fusion (TLIF) for degenerative spine conditions.

SUMMARY OF BACKGROUND DATA

There is conflicting data on the effect of smoking on long-term functional outcomes following lumbar fusion. Moreover, there remains a paucity of literature on the influence of smoking within the field of minimally invasive spine surgery.

METHODS

Prospectively collected registry data of nondiabetic patients who underwent primary single-level minimally invasive TLIF in a single institution was reviewed. Patients were stratified based on smoking history. All patients were assessed preoperatively and postoperatively using the Numerical Pain Rating Scale for back pain and leg pain, Oswestry Disability Index, Short-Form 36 Physical and Mental Component Scores. Satisfaction was assessed using the North American Spine Society questionnaire. Radiographic fusion rates were compared.

RESULTS

In total, 187 patients were included, of which 162 were nonsmokers, and 25 had a positive smoking history. In our multivariate analysis, smoking history was insignificant in predicting for minimal clinically important difference attainment rates in Physical Component Score and fusion grading outcomes. However, in terms of satisfaction score, positive smoking history remained a significant predictor (odds ratio=4.7, 95% confidence interval: 1.10-20.09, P=0.036).

CONCLUSIONS

Nondiabetic patients with a positive smoking history had lower satisfaction scores but comparable functional outcomes and radiologic fusion 2 years after single-level TLIF. Thorough preoperative counseling and smoking cessation advice may help to improve patient satisfaction following minimally invasive spine surgery.

LEVEL OF EVIDENCE

Level III-nonrandomized cohort study.

Fracture, nonunion and postoperative infection risk in the smoking orthopaedic patient: a systematic review and meta-analysis

This systematic review and meta-analysis aimed to analyse negative effects of smoking in orthopaedic and trauma patients.

A PubMed search was carried out for studies published until July 2020 regarding effects of smoking on fracture risk, nonunion, infection after orthopaedic surgery, and persisting nonunion after scaphoid nonunion surgery. Random effects models calculated for outcome parameters, and relative risks (RR) with 95% confidence intervals are provided. No adjustments for covariates were made. Heterogeneity was assessed with Higgins’ I2, publication bias with Harbord’s p (Hp), sensitivity analysis performed on funnel plots and quality of studies was analysed using the Newcastle-Ottawa Scale.

Of 3362 retrieved entries, 69 were included in the final analysis. Unadjusted RR for smokers to develop vertebral (six studies, seven entries; RR: 1.61; p = 0.008; I2 = 89.4%), hip (11 studies, 15 entries; RR: 1.28; p = 0.007; I2 = 84.1%), and other fractures (eight studies, 10 entries; RR: 1.75; p = 0.019; I2 = 89.3%) was significantly higher. Postoperative infection risk was generally higher for smokers (21 studies; RR: 2.20; p < 0.001; I2 = 58.9%), and remained upon subgroup analysis for elective spinal (two studies; RR: 4.38; p < 0.001; I2 = 0.0%) and fracture surgery (19 studies; RR: 2.10; p < 0.001; I2 = 58.5%). Nonunion risk after orthopaedic (eight studies; RR: 2.15; p < 0.001; I2 = 35.9%) and fracture surgery (11 studies; RR: 1.85; p < 0.001; I2 = 39.9%) was significantly higher for smokers, as was persisting nonunion risk after surgery for scaphoid nonunion (five studies; RR: 3.52; p < 0.001; I2 = 0.0%). Sensitivity analysis for each model reduced heterogeneity whilst maintaining significance (all I2 < 20.0%).

Smoking has a deleterious impact on fracture incidence, and (subsequent) development of nonunions and postoperative infections.

Cite this article: EFORT Open Rev 2021;6:1006-1019. DOI: 10.1302/2058-5241.6.210058

Amelioration of Nicotine-Induced Osteoarthritis by Platelet-Derived Biomaterials Through Modulating IGF-1/AKT/IRS-1 Signaling Axis

Besides inhalation, a few studies have indicated that the uptake of nicotine through air or clothing may be a significant pathway of its exposure among passive smokers. Nicotine is well known to exert various physiological impacts, including stimulating sympathetic nervous system, causing vascular disturbances, and inducing cell death. Therefore, we aimed to establish whether exposure of nicotine could induce articular cartilage degeneration in a mouse model of osteoarthritis (OA). We specifically assessed dose-dependent effect of nicotine in vitro to mimic its accumulation. Further, during the in vivo studies, mice subcutaneously administered with nicotine was examined for OA-associated pathologic changes. We found that nicotine significantly suppressed chondrocytes and chondrogenic markers (Sox, Col II, and aggrecan). Nicotine-treated mice also showed altered knee joint ultrastructure with reduced Col II and proteoglycans. After corroborating nicotine-induced OA characteristics, we treated this pathologic condition through employing platelet-derived biomaterial (PDB)-based regenerative therapy. The PDB significantly suppressed OA-like pathophysiological characteristics by 4 weeks. The mechanistic insight underlying this therapy demonstrated that PDB significantly restored levels of insulin-like growth factor 1 (IGF-1) signaling pathway proteins, especially pIGF-1 R, pAKT, and IRS-1, regulating extracellular matrix synthesis by chondrocytes. Taken together, the PDB exerts regenerative and reparative activities in nicotine-mediated initiation and progression of OA, through modulating IGF-1/AKT/IRS-1 signaling axis.

Failure to Optimize Before Total Knee Arthroplasty: Which Modifiable Risk Factor is the Most Dangerous?

BACKGROUND

Complications after total knee arthroplasty (TKA) are devastating for patients, and surgeons are held accountable in alternative payment models. Optimization of modifiable risk factors has become a mainstay in the preoperative period. We sought to evaluate the consequence of failure to optimize key risk factors in a modern cohort of patients who underwent TKA.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program database was searched to identify patients who underwent TKA in 2017-2018. Patients were considered optimized if they had a body mass index <40kg/m², had albumin >3.5g/dL, were nonsmokers, and were nondiabetic. Patients were then grouped based on the previous 4 risk factors. Thirty-day readmission, infection, general complications, and mortality were analyzed and compared between the groups.

RESULTS

Overall, 84,315 patients were included in the study. A total of 31.6% of patients were not considered optimized. Body mass index >40kg/m², albumin <3.5, smoking, and insulin-dependent diabetes were all found to be associated with postoperative infection, readmission, mortality, and complication in general (P < .05). When compared, the nonoptimized group was found to have significantly higher risk of readmission (5 vs 3%), infection (2 vs 1%), general complications (8 vs 5%), and mortality (0.35 vs 0.1%) (all P < .001). Logistic regression showed that those with albumin less than 3.5g/dL had 3.7-fold higher odds of infection and 7.2-fold higher odds of 30-day mortality.

CONCLUSION

Despite knowledge that modifiable risk factors significantly influence postoperative outcomes, surgeons continue to operate on patients who are not optimized. Among the modifiable risk factors analyzed, hypoalbuminemia appears to be the strongest risk factor for all complications evaluated. Special attention should be paid to preoperative nutritional optimization.

LEVEL OF EVIDENCE

Retrospective cohort study, level IV.

Type of bone graft and primary diagnosis were associated with nosocomial surgical site infection after high tibial osteotomy: analysis of a national database

PURPOSE

Although several small-scale studies have reported risk factors for surgical site infection (SSI) after high tibial osteotomy (HTO), no study has collectively analysed risk factors in a large cohort. The present study aimed to clarify the risk factors for SSI after HTO using a national database.

METHODS

Data of inpatients who underwent HTO from 2010 to 2017 were obtained from the Diagnosis Procedure Combination database in Japan. Outcome measures were the incidence of SSI and deep SSI after HTO. Associations between SSI and patient data were examined with multivariable logistic regression analysis.

RESULTS

Among 12,853 patients who underwent HTO, 195 developed SSI (1.52%) and 50 developed deep SSI (0.39%). Univariate analysis showed that male sex, smoking, and longer anaesthesia duration were associated with higher incidences of SSI, whereas a primary diagnosis of osteonecrosis and use of natural bone grafts were associated with lower incidences. In multivariable analysis, SSI was positively associated with male sex, anaesthesia duration longer than 210 min (vs. 150-210 min), and use of artificial bone graft (vs. natural bone graft). SSI was negatively associated with age ≤ 49 years (vs. 50-59 years) and a primary diagnosis of osteonecrosis (vs. osteoarthritis).

CONCLUSION

The present study revealed novel risk factors for SSI after HTO that previous studies have failed to find, including use of artificial bone graft and longer anaesthesia duration; primary diagnosis of osteonecrosis and younger age were novel protective factors. These findings will help surgeons assess risks of SSI after HTO in individual patients.

LEVEL OF EVIDENCE

III.

Association of Urinary and Blood Concentrations of Heavy Metals with Measures of Bone Mineral Density Loss: a Data Mining Approach with the Results from the National Health and Nutrition Examination Survey

Osteoporosis and its consequence of fragility fracture represent a major public health problem. Human exposure to heavy metals has received considerable attention over the last decades. However, little is known about the influence of co-exposure to multiple heavy metals on bone density. The present study aimed to examine the association between exposure to metals and bone mineral density (BMD) loss. Blood and urine concentrations of 20 chemical elements were selected from 3 cycles (2005-2010) NHANES (National Health and Nutrition Examination Survey), in which we included white women over 50 years of age and previously selected for BMD testing (N = 1892). The bone loss group was defined as participants having T-score < - 1.0, and the normal group was defined as participants having T-score ≥ - 1.0. We developed classification models based on support vector machines capable of determining which factors could best predict BMD loss. The model which included the five-best features-selected from the random forest were age, body mass index, urinary concentration of arsenic (As), cadmium (Cd), and tungsten (W), which have achieved high scores for accuracy (92.18%), sensitivity (90.50%), and specificity (93.35%). These data demonstrate the importance of these factors and metals to the classification since they alone were capable of generating a classification model with a high prediction of accuracy without requiring the other variables. In summary, our findings provide insight into the important, yet overlooked impact that arsenic, cadmium, and tungsten have on overall bone health.

Supramolecular self-assembling peptides to deliver bone morphogenetic proteins for skeletal regeneration

Recombinant human bone morphogenetic proteins (BMPs) have shown clinical success in promoting bone healing, but they are also associated with unwanted side effects. The development of improved BMP carriers that can retain BMP at the defect site and maximize its efficacy would decrease the therapeutic BMP dose and thus improve its safety profile. In this review, we discuss the advantages of using self-assembling peptides, a class of synthetic supramolecular biomaterials, to deliver recombinant BMPs. Peptide amphiphiles (PAs) are a broad class of self-assembling peptides, and the use of PAs for BMP delivery and bone regeneration has been explored extensively over the past decade. Like many self-assembling peptide systems, PAs can be designed to form nanofibrous supramolecular biomaterials in which molecules are held together by non-covalent bonds. Chemical and biological functionality can be added to PA nanofibers, through conjugation of chemical moieties or biological epitopes to PA molecules. For example, PA nanofibers have been designed to bind heparan sulfate, a natural polysaccharide that is known to bind BMPs and potentiate their signal. Alternatively, PA nanofibers have been designed to synthetically mimic the structure and function of heparan sulfate, or to directly bind BMP specifically. In small animal models, these bio-inspired PA materials have shown the capacity to promote bone regeneration using BMP at doses 10-100 times lower than established therapeutic doses. These promising results have motivated further evaluation of PAs in large animal models, where their safety and efficacy must be established before clinical translation. We conclude with a discussion on the possiblity of combining PAs with other materials used in orthopaedic surgery to maximize their utility for clinical translation.

Risk Factors related to Late Failure of Dental Implant-A Systematic Review of Recent Studies

Resolving late failure of dental implant is difficult and costly; however, only few reviews have addressed the risk factors associated with late failure of dental implant. The aim of this literature review was to summarize the influences of different potential risk factors on the incidence of late dental implant failure. The protocol of this systematic review was prepared and implemented based on the PRISMA (Preferred reporting items for systematic reviews and meta-analyses) guideline. In December 2018, studies published within the previous 10 years on late dental implant failure were selected by fulfilling the eligibility criteria and the risk factors identified in qualified studies were extracted by using a predefined extraction template. Fourteen eligible studies were assessed. The common risk factors for late failure were divided into three groups according to whether they were related to (1) the patient history (radiation therapy, periodontitis, bruxism and early implant failure), (2) clinical parameters (posterior implant location and bone grade 4) or (3) decisions made by the clinician (low initial stability, more than one implant placed during surgery, inflammation at the surgical site during the first year or using an overdenture with conus-type connection). Clinicians should be cautions throughout the treatment process of dental implant-from the initial examination to the treatment planning, surgical operation and prosthesis selection-in order to minimize the risk of late failure of dental implant.

Relationship Between Time to Surgical Debridement and the Incidence of Infection in Patients with Open Tibial Fractures

OBJECTIVE

To analyze the relationship between the length from injury to first debridement (LFITFD) of open tibial fractures and perioperative infection, and explore independent risk factors related to infection.

METHODS

This retrospective study focused on 215 clinical patients with open tibial fractures who were admitted from January 2012 to January 2017. According to the time from injury to the operation, the patients were categorized into four groups: LFITFD ≤ 6 h, 6 < LFITFD ≤ 12 h, 12 < LFITFD≤24 h, and (LFITFD > 24 h). Infection risk factors were screened by univariate analysis, and multivariate logistic regression analysis was used to determine independent risk factors.

RESULTS

The infection rates of four groups were 9.2%, 9.5%, 11.1%, and 10.5% with six of 65, nine of 95, four of 36, and two of 19 patients being infected, respectively. There was no statistical significance between the four groups. The infection rates among fractures of different Gustilo-Anderson classifications were as follows. Of 62 cases of type I fractures, two were infected, and the infection rate was 3.2%. Among those with type II fractures, eight were infected, and the infection rate was 8.2%. Three of 26 cases of type IIIA fracture were infected, yielding an infection rate of 11.5%, seven of 25 cases of type III B fracture were infected (28% infection rate), and one of four cases of type III C fracture was infected (25% infection rate). There was a statistically significant difference between the five groups. Multivariate regression analysis showed that smoking, combined diabetes, surgical time, and fracture Gustilo-Anderson classification were independent risk factors for perioperative infection of open tibial fractures, and the difference in time from injury to first debridement was not related to infection.

CONCLUSION

The incidence of perioperative infection in patients with open tibial fractures has little to do with the time of the first debridement, which is mainly related to the level of the fracture's Gustilo-Anderson classification. At the same time, smoking is prohibited before the operation, the patient's blood glucose is managed, and the debridement operation time is minimized conducive to reducing the incidence of infection.

Does surgical approach affect sagittal plane alignment and pilon fracture outcomes?

PURPOSE

Sagittal plane alignment beyond articular reduction and its effect on clinical outcomes has not been emphasized. Surgical approach may influence a surgeon's ability to correct the sagittal plane alignment. The purpose of our study was to evaluate how surgical approach impacts anterior distal tibial angle (ADTA) and lateral talar station (LTS). Our hypothesis was that the anterolateral (AL) approach would improve the sagittal plane parameters due to the primary plate placement.

PATIENTS AND METHODS

A retrospective review was performed on patients who underwent operative management for pilon fractures at 2 ACS Level 1 Academic Trauma Centers. Clinical data points including demographics, comorbidities, AO/OTA classification, surgical approach, and complications were recorded. Quality of reduction was measured using the ADTA, lateral distal tibia angle (LDTA), and lateral talar station (LTS) from radiographs.

RESULTS

580 pilon fractures met inclusion criteria. When compared to the AL approach, the modified anteromedial (AM) approach had decreased rates of local wound care, and unplanned reoperations. The AM approach had increased rates of superficial infection, deep infection, non-union, and amputations. There was no difference in ADTA, LDTA, or LTS between the AM and AL approach (P = 0.49, P = 0.41, P = 0.85). There was a difference in LTS with tobacco users (P = 0.02).

CONCLUSIONS

The sagittal plane alignment does not appear to be affected by the surgical approach. Therefore, the surgical approach to pilon fractures should be based on the fracture pattern and the patient's soft tissue envelope. This study shows that the AM is a relatively safe and effective approach to complex fractures and the surgeon should consider the specific fracture pattern and patient soft tissue envelope when choosing the specific approach.

Association of Nicotine with Osteochondrogenesis and Osteoarthritis Development: The State of the Art of Preclinical Research

The deleterious effects of nicotine on various health conditions have been well documented. Although many orthopedic diseases are adversely affected by nicotine, little is known about its preclinical effects on chondrogenesis or osteogenesis, cartilage formation, osteoarthritis (OA), and osteochondral repair. A systematic review was conducted examining the current scientific evidence on the effects of nicotine on chondrogenesis or osteogenesis in vitro, possible consequences of prenatal nicotine exposure (PNE) on cartilage and OA susceptibility in the offspring, and whether nicotine affects OA development and osteochondral repair in vivo, always focusing on their underlying mechanisms. The data reveal dose-dependent effects on articular chondrocytes and on the chondrogenesis and osteogenesis of medicinal signaling cells in vitro, with lower doses often resulting in positive effects and higher doses causing negative effects. PNE negatively affects articular cartilage development and induces OA in the offspring without or with nicotine exposure. In contrast, protective effects on OA development were only reported in monosodium iodoacetate-induced small animal models. Finally, nicotine repressed MSC-based osteochondral repair in vivo. Future studies need to investigate dose-dependent clinical effects of smoking on cartilage quality in offspring, OA susceptibility and progression, and osteochondral repair more in detail, thus identifying possible thresholds for its pathological effects.

Risk Factors for Low Back Pain: A Population-Based Longitudinal Study

OBJECTIVE

To identify risk factors for low back pain (LBP) and lumbar radicular pain and to assess whether obesity and exposure to workload factors modify the effect of leisure-time physical activity on LBP and lumbar radicular pain.

METHODS

The population of this 11-year longitudinal study consists of a nationally representative sample of Finns ages ≥30 years (n = 3,505). The outcomes of the study were LBP and lumbar radicular pain for >7 days or for >30 days in the past 12 months at follow-up.

RESULTS

LBP and lumbar radicular pain were more common in women than in men. LBP slightly declined with increasing age, while lumbar radicular pain increased with age. Abdominal obesity (defined by waist circumference) increased the risk of LBP (adjusted odds ratio [OR] 1.40 [95% confidence interval (95% CI) 1.16-1.68] for LBP >7 days and adjusted OR 1.41 [95% CI 1.13-1.76] for LBP >30 days) and general obesity (defined by body mass index) increased the risk of lumbar radicular pain (adjusted OR 1.44 [95% CI 1.12-1.85] for pain >7 days and adjusted OR 1.62 [95% CI 1.16-2.26] for pain >30 days). Smoking and strenuous physical work increased the risk of both LBP and lumbar radicular pain. Walking or cycling to work reduced the risk of LBP, particularly LBP for >30 days (adjusted OR 0.75 [95% CI 0.59-0.95]), with the largest reductions among nonabdominally obese individuals and among those not exposed to physical workload factors. Using vibrating tools increased the risk of lumbar radicular pain.

CONCLUSION

Lifestyle and physical workload factors increase the risk of LBP and lumbar radicular pain. Walking and cycling may have preventive potential for LBP.

Smoking is associated with increased complications and readmission following extensor mechanism repair

PURPOSE

Extensor mechanism injuries are disabling injuries that require prompt evaluation and treatment and complications are often devastating. While smoking has been shown to increase complications following total joint arthroplasty, this relationship has not yet been established in those undergoing extensor mechanism repair. The purpose of this study was to evaluate the risk of smoking on postoperative complications following extensor mechanism repair.

METHODS

The National Surgical Quality Improvement Program (NSQIP) database was used to identify patients who underwent an extensor mechanism repair from 2005 to 2016. Patients were stratified by tobacco use, as either "current" or "nonsmokers." A multivariate logistic regression was used to control for demographic and comorbid factors while assessing perioperative complications.

RESULTS

5208 patients were identified, and of these, 843 (16.2%) were current smokers. Smokers were younger, male, and with lower BMIs compared to nonsmokers (p = 0.001, p = 0.003, p = 0.002, respectively). They had a higher rate of surgical complications (OR 1.61, CI 1.02-2.52), including deep surgical site infections (OR 3.27, CI 1.03-10.43) and unplanned return to the operating room (OR 2.001, 1.24-3.23). Smokers were more likely to be readmitted within 30 days of surgery (OR 1.78, OR 1.09-2.90).

CONCLUSION

Tobacco use is associated with a 1-2% increase in surgical, but not medical, complications following repair of extensor mechanism injuries. Smokers are at higher risk for deep infections, unplanned return to the OR, and hospital readmission. Identifying these patients preoperatively will allow surgeons to accurately counsel patients on perioperative risks. Counseling in preoperative smoking cessation is valuable for optimizing patient outcomes following extensor mechanism repair.

LEVEL OF EVIDENCE

Retrospective comparative study, Level III.

Unilateral Laminotomy with Bilateral Decompression: A Case Series Studying One- and Two-Year Outcomes with Predictors of Minimal Clinical Improvement

OBJECTIVE

To assess factors that may predict failure to improve at 12 and 24 months after unilateral laminotomy with bilateral decompression (ULBD) for the management of lumbar spinal stenosis.

METHODS

A database of 255 patients who underwent microdecompression surgery by a single orthopedic spine surgeon between 2014 and 2018 was queried. Patients who underwent primary single-level ULBD of the lumbar spine were included. Visual analog scale (VAS) for back pain and leg pain and Oswestry Disability Index (ODI) results were collected preoperatively and at 12 and 24 months postoperatively. Demographic, radiographic, and operative factors were assessed for associations with failure to improve. Clinically important improvement was defined as reaching or surpassing the previously established minimum clinically important difference for ODI (12.8) and not requiring revision.

RESULTS

A total of 68 patients were included. Compared with preoperative values for back pain, leg pain, and ODI (7.32, 7.53, and 51.22, respectively), there were significant improvements on follow-up at 12 months (2.89, 2.23, and 22.40, respectively; P < 0.001) and 24 months (2.80, 2.11, 20.32, respectively; P < 0.001). Based on the defined criteria, 50 patients showed clinically important improvement after ULBD. Of the 18 patients who failed to improve, 12 required revision. Independent predictors of failure to improve included female sex (adjusted odds ratio, 5.06; 95% confidence interval, 1.49-21.12; P = 0.014) and current smoker status (adjusted odds ratio, 5.39; 95% confidence interval, 1.39-23.97; P = 0.018).

CONCLUSIONS

ULBD for the management of lumbar spinal stenosis leads to clinically important improvement that is maintained over a 24-month follow-up period. Female sex and tobacco smoking are associated with poorer outcomes.

Negative Predictors of Outcomes of Flexor Tendon Repairs

The current trend in hand surgery has streamlined the treatment of acute hand trauma to the modern-day surgery unit. As the volume of hand trauma caseloads continues to increase, it is becoming increasingly difficult to schedule patients for theater on the day of injury. It, therefore, becomes paramount to adequately triage patients in accordance with best clinical evidence and predictors of poor clinical outcomes.

Animal models suggest that the earlier flexor tendons are repaired, the better the patient functional outcome. The largest study to date examining the timing of injury to functional post-operative outcome also recognizes that the faster these injuries are repaired, the better the patient outcome. Age-related changes to tendon biomechanics and structure are well-documented. However, no conclusive evidence exists specific to the degenerative changes and mechanical properties of flexor tendons in humans. The animal model strongly suggests that increasing age is associated with local architectural and biological changes that directly affect the tendon repair functional outcome. Although retrospective analyses to date suggest that smoking is a negative outcome predictor for functional tendon outcome, no prospective large-scale studies exist.

A large, single-center prospective study specifically examining the positive and negative outcome predictors of flexor tendon repairs and functional post-operative outcome is warranted. The negative predictive model of patient care may enable us to further council patients preoperatively and stratify patients according to clinical need.

Effect of Cigarette Smoking on Patient-Reported Outcomes in Hip Arthroscopic Surgery: A Matched-Pair Controlled Study With a Minimum 2-Year Follow-up

Background

The rate of hip arthroscopic surgery has recently increased; however, there is limited literature examining patient-reported outcomes (PROs) in cigarette smokers.

Purpose/Hypothesis

The purpose of this study was to evaluate whether smoking status for patients undergoing hip arthroscopic surgery affects clinical findings and PRO scores. We hypothesized that patients who smoke and undergo primary hip arthroscopic surgery will have similar clinical examination findings and preoperative and postoperative PRO scores compared with nonsmoking patients.

Study Design

Cohort study; Level of evidence, 3.

Methods

Data were collected on all patients who underwent primary hip arthroscopic surgery from February 2008 to July 2015. A retrospective analysis of the data was then conducted to identify patients who reported cigarette use at the time of the index procedure. Patients were matched 1:2 (smoking:nonsmoking) based on sex, age within 5 years, labral treatment (repair vs reconstruction vs debridement), workers' compensation status, and body mass index within 5 kg/m². All patients were assessed preoperatively and postoperatively using 4 PRO measures: the modified Harris Hip Score (mHHS), Non-Arthritic Hip Score (NAHS), Hip Outcome Score-Sport-Specific Subscale (HOS-SSS), and International Hip Outcome Tool-12 (iHOT-12). Pain was estimated using a visual analog scale. Satisfaction was measured on a scale from 0 to 10. Significance was set at P < .05.

Results

A total of 75 hips were included in the smoking group, and 150 hips were included in the control group. Preoperatively, the smoking group had significantly lower PRO scores compared with the control group for the mHHS, NAHS, and HOS-SSS. Both groups demonstrated significant improvement from preoperative levels. A minimum 2-year follow-up was achieved, with a mean of 42.5 months for the smoking group and 47.6 months for the control group (P = .07). At the latest follow-up, the smoking group reported inferior results for all outcome measures compared with controls. The improvement in PRO scores and rates of treatment failure, revision arthroscopic surgery, and complications was not statistically different between the groups.

Conclusion

Patients who smoke had lower PRO scores preoperatively and at the latest follow-up compared with nonsmokers. Both groups demonstrated significant improvement in all PRO scores. These results show that while hip arthroscopic surgery may still yield clinical benefit in smokers, these patients may ultimately achieve an inferior functional status. To optimize results, physicians should advise patients to cease smoking before undergoing hip arthroscopic surgery.

Tobacco Use and Risk of Wound Complications and Periprosthetic Joint Infection: A Systematic Review and Meta-Analysis of Primary Total Joint Arthroplasty Procedures

BACKGROUND

The purpose of this study was to perform a systematic review and meta-analysis to quantitatively assess the association between tobacco use and the risk of any wound complication and periprosthetic joint infection (PJI) after primary total hip and total knee arthroplasty procedures.

METHODS

Relevant articles published before January 2018 were identified by systematically searching PubMed, EMBASE, and Cochrane library databases. Pooled odds ratios (OR) and 95% confidence intervals were calculated for end points of any wound complication and PJI. Additional analyses were performed to evaluate risks between current, former, and non-tobacco users.

RESULTS

Fourteen studies were included in the meta-analysis. Tobacco users had a significantly higher risk of wound complications (OR, 1.78 [1.32-2.39]) and PJI (OR, 2.02 [1.47-2.77]) compared to non-tobacco users. Compared to non-tobacco users, there was an increased risk of PJI among current (OR, 2.16 [1.57-2.97] and former (OR, 1.52 [1.16-1.99]) tobacco users. Current tobacco users also had a significantly increased risk of PJI compared to former tobacco users (OR, 1.52 [1.07-2.14]).

CONCLUSION

Tobacco use before total hip and total knee arthroplasty significantly increases the risk of wound complications and PJI. This increased risk is present for both current and former tobacco users. However, former tobacco users had a significantly lower risk of wound complications and PJI compared to current tobacco users, suggesting that cessation of tobacco use before TJA can help to mitigate these observed risks.

Aryl Hydrocarbon Receptor Antagonists Mitigate the Effects of Dioxin on Critical Cellular Functions in Differentiating Human Osteoblast-Like Cells

The inhibition of bone healing in humans is a well-established effect associated with cigarette smoking, but the underlying mechanisms are still unclear. Recent work using animal cell lines have implicated the aryl hydrocarbon receptor (AhR) as a mediator of the anti-osteogenic effects of cigarette smoke, but the complexity of cigarette smoke mixtures makes understanding the mechanisms of action a major challenge. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD, dioxin) is a high-affinity AhR ligand that is frequently used to investigate biological processes impacted by AhR activation. Since there are dozens of AhR ligands present in cigarette smoke, we utilized dioxin as a prototype ligand to activate the receptor and explore its effects on pro-osteogenic biomarkers and other factors critical to osteogenesis using a human osteoblast-like cell line. We also explored the capacity for AhR antagonists to protect against dioxin action in this context. We found dioxin to inhibit osteogenic differentiation, whereas co-treatment with various AhR antagonists protected against dioxin action. Dioxin also negatively impacted cell adhesion with a corresponding reduction in the expression of integrin and cadherin proteins, which are known to be involved in this process. Similarly, the dioxin-mediated inhibition of cell migration correlated with reduced expression of the chemokine receptor CXCR4 and its ligand, CXCL12, and co-treatment with antagonists restored migratory capacity. Our results suggest that AhR activation may play a role in the bone regenerative response in humans exposed to AhR activators, such as those present in cigarette smoke. Given the similarity of our results using a human cell line to previous work done in murine cells, animal models may yield data relevant to the human setting. In addition, the AhR may represent a potential therapeutic target for orthopedic patients who smoke cigarettes, or those who are exposed to secondhand smoke or other environmental sources of aryl hydrocarbons.

Treatment of critical-sized bone defects: clinical and tissue engineering perspectives

Critical-sized bone defects are defined as those that will not heal spontaneously within a patient's lifetime. Current treatment options include vascularized bone grafts, distraction osteogenesis, and the induced membrane technique. The induced membrane technique is an increasingly utilized method with favorable results including high rates of union. Tissue engineering holds promise in the treatment of large bone defects due to advancement of stem cell biology, novel biomaterials, and 3D bioprinting. In this review, we provide an overview of the current operative treatment strategies of critical-sized bone defects as well as the current state of tissue engineering for such defects.

Clinical outcomes following surgically repaired bucket-handle meniscus tears

OBJECTIVES

Meniscus tears are one of the most common knee injuries. Our goal is to investigate the failure rate for surgically repaired bucket-handle meniscus tears and compare clinical outcomes of repairs that failed versus those that did not, at a minimum 2-year follow-up interval.

METHODS

51 patients were identified in this retrospective cohort study who experienced bucket-handle meniscus tears that were isolated or with concomitant ACL injury. Inclusion criteria included age range from 13-55 years, confirmed bucket-handle meniscus tear by MRI and intraoperatively, and at least two-years of post-operative follow-up following index repair. Demographic data and outcome surveys were collected at a minimum of two-years follow-up after repair.

RESULTS

Of the 51 patients that had a bucket-handle meniscal repair, 12 (23.5%) were defined as failures (return of symptoms alongside re-tear in the same zone of the repaired meniscus within two years of surgery). No demographic variables (age, sex, and BMI smoking status, location of tear, or concomitant ACL tear) significantly correlated with failure. The mean of the Sports and Recreation KOOS was significantly lower between the non-failure (87 ± 14.4) and failure (70 ± 17.2) cohorts (p = 0.0072). The Quality of Life subscale was significantly lower between the non-failure (76 ± 15.8) and failure (57 ± 18.2) groups (p = 0.0058). There was a significant difference in the post-operative Lysholm scores (p = 0.0039) with a mean of 90 ± 9.1 for the entire cohort and means of 92 ± 8.4 and 83 ± 8.6, for non-failure and failure groups, respectively.

CONCLUSIONS

We found a higher failure rate (23.5%) for bucket-handle meniscus repairs at two-year follow up than has been cited in the literature, which is typically less than 20%, with significantly lower KOOS Quality of Life and Sports and Recreation subscales and Lysholm scores for the failure cohort. This is the first study to report these outcome scores solely for bucket-handle meniscus repairs, shedding light on the post-operative quality of life of patients with repair success or failure.

Descriptive Epidemiology, Medical Evaluation, and Outcomes of Rock Climbing Injuries

OBJECTIVE

To gather epidemiologic data on injury type, treatment, and recovery from rock climbing injuries.

METHODS

Design: retrospective cross-sectional study.

SETTING

web-based survey.

PARTICIPANTS

rock climbers who sustained a climbing-related injury during the prior 24 months. Criteria for inclusion: aged ≥18 years; participation in rock climbing at least 4 times per year in the United States.

INTERVENTIONS

none.

MAIN OUTCOME MEASURES

percentage of injured climbers seeking medical care, providers seen, subspecialty referral, development of chronic problems, factors affecting return to climbing, injuries by climbing type, body region, and injury type.

RESULTS

Data were collected over a 60-day period using the Research Electronic Data Capture (REDCap) survey system. Seven hundred and eight surveys were collected from 553 male and 155 female climbers. Thirteen hundred ninety seven injuries were reported, and 975 injuries were suitable for analysis. The most common provider initially seen was a primary care provider. Subspecialty referral was commonly obtained. Injury patterns differed by climbing type. The percentage of respondents that returned to climbing before their injury was fully healed was 51.1%, and 44.9% of respondents developed chronic problems related to their climbing injury. Twenty-eight percent of respondents were unable to return to their previous level of climbing performance. Several factors were associated with delayed recovery from climbing injury.

CONCLUSIONS

A significant number of climbers sought healthcare after injury. A majority of climbers who sought treatment were referred to subspecialist providers. About one-half of climbers were symptomatic when they returned to climbing and developed chronic problems after injury. Factors associated with slower return to climbing included increasing age, smoking, fractures, and surgery.

The Clinical Correlations between Diabetes, Cigarette Smoking and Obesity on Intervertebral Degenerative Disc Disease of the Lumbar Spine

Study Design

Retrospective analysis of a nationwide private insurance database. Chi-square analysis and linear regression models were utilized for outcome measures.

Purpose

The purpose of this study was to investigate any relationship between lumbar degenerative disc disease, diabetes, obesity and smoking tobacco.

Overview of Literature

Diabetes, obesity, and smoking tobacco are comorbid conditions known to individually have effect on degenerative disc disease. Most studies have only been on a small populous scale. No study has yet to investigate the combination of these conditions within a large patient cohort nor have they reviewed the combination of these conditions on degenerative disc disease.

Methods

A retrospective analysis of insurance billing codes within the nationwide Humana insurance database was performed, using PearlDiver software (PearlDiver, Inc., Fort Wayne, IN, USA), to identify trends among patients diagnosed with lumbar disc degenerative disease with and without the associated comorbidities of obesity, diabetes, and/or smoking tobacco. Patients billed for a comorbidity diagnosis on the same patient record as the lumbar disc degenerative disease diagnosis were compared over time to patients billed for lumbar disc degenerative disease without a comorbidity. There were no sources of funding for this manuscript and no conflicts of interest.

Results

The total number and prevalence of patients (per 10,000) within the database diagnosed with lumbar disc degenerative disease increased by 241.4% and 130.3%, respectively. The subsets of patients within this population who were concurrently diagnosed with either obesity, diabetes, tobacco use, or a combination thereof, was significantly higher than patients diagnosed with lumbar disc degenerative disease alone (p <0.05 for all). The number of patients diagnosed with lumbar disc degenerative disease and smoking rose significantly more than patients diagnosed with lumbar disc degenerative disease and either diabetes or obesity (p <0.05). The number of patients diagnosed with lumbar disc degenerative disease, smoking and obesity rose significantly more than the number of patients diagnosed with lumbar disc degenerative disease and any other comorbidity alone or combination of comorbidities (p <0.05).

Conclusions

Diabetes, obesity and cigarette smoking each are significantly associated with an increased diagnosis of lumbar degenerative disc disease. The combination of smoking and obesity had a synergistic effect on increased rates of lumbar degenerative disc disease. Patient education and preventative care is a vital goal in prevention of degenerative disc disease within the general population.

Risk Factors in Early Implant Failure: A Meta-Analysis

BACKGROUND

Clinicians should be able to weigh the role of the main risk factors associated with early implant failure.

PURPOSE

The aim of this meta-analysis was to assess the influence of different patient-related and implant-related risk factors on the occurrence of early implant failure.

MATERIALS AND METHODS

In July, 2014 the main electronic databases were searched for studies reporting on early failures. Relevant papers were selected by 2 independent authors using predefined selection criteria. Three authors independently scored the included studies for quality assessment. The estimated odds ratios of the main risk factors from the selected papers were subjected to meta-analysis.

RESULTS

Nine studies were included. A total of 18,171 implants were meta-analyzed, of which 10,921 were analyzed for smoking, 15,260 for implant diameter, 16,075 for implant length, and 16,711 for implant location (maxilla vs mandible). The main significant risk factors for early implant failures were the smoking habit (odds ratio [OR], 1.7; 95% confidence interval [CI], 1.3, 2.3), implants shorter than 10 mm (OR, 1.6; 95% CI, 1.2, 2.2) and implants placed in the maxilla (OR, 1.3; 95% CI, 1.0, 1.6).

CONCLUSIONS

Clinicians should be aware of the increased risk of early failure in the presence of smokers, implants with reduced length, and implant-supported maxillary rehabilitation.

Incidence and Risk Factors of Postoperative Hematoma Requiring Reoperation in Single-level Lumbar Fusion Surgery

STUDY DESIGN

Retrospective cohort.

OBJECTIVE

The purpose of the present study was to examine the incidence and risk factors for postoperative hematoma requiring reoperation in patients undergoing single-level lumbar fusion surgery.

SUMMARY OF BACKGROUND DATA

Postoperative hematoma can cause devastating neurological consequences after spine surgery. Risk factors for hematoma in specific spine procedures have not been well established.

METHODS

A cohort of patients undergoing single-level lumbar fusion surgery was constructed from the 2012 to 2013 American College of Surgeons National Surgical Quality Improvement Program dataset using Current Procedural Terminology codes (22533, 22558, 22612, 22630, and 22633). In cases requiring reoperation within 30 days after initial surgery, postoperative hematoma was identified using the ICD-9 code 998.1. Risk factors for postoperative hematoma were assessed with logistic regression modeling.

RESULTS

Of 5280 patients undergoing single-level lumbar fusion surgery, 27 patients (0.5%) developed a postoperative hematoma requiring reoperation for hematoma evacuation. A heightened incidence of postoperative hematoma was found in patients who were smokers (1.0% vs. 0.4% for nonsmokers, P = 0.016) or who had a diagnosis of bleeding disorder (3.8% vs. 0.5% for those without bleeding disorder, P = 0.007). Multivariate logistic regression analysis indicated that the adjusted odds ratios for postoperative hematoma associated with smoking and bleeding disorder were 3.34 (95% confidence interval, 1.15-9.71) and 10.2 (95% confidence interval, 1.9-54.8), respectively.

CONCLUSION

Smoking and bleeding disorder appear to be major risk factors for postoperative hematoma requiring reoperation after single-level lumbar fusion surgery. Intervention programs targeting patients with these risk factors are needed to reduce their excess risk of postoperative hematoma.

LEVEL OF EVIDENCE

3.

Preoperative estimation of disc herniation recurrence after microdiscectomy: predictive value of a multivariate model based on radiographic parameters

BACKGROUND CONTEXT

Recurrence of lumbar disc herniation (rLDH) is one of the unfavorable outcomes after microdiscectomy. Prediction of the patient population with increased risk of rLDH is important because patients may benefit from preventive measures or other surgical options.

PURPOSE

The study assessed preoperative factors associated with rLDH after microdiscectomy and created a mathematical model for estimation of chances for rLDH.

STUDY DESIGN/SETTING

This is a retrospective case-control study.

PATIENT SAMPLE

The study includes patients who underwent microdiscectomy for LDH.

OUTCOME MEASURES

Lumbar disc herniation recurrence was determined using magnetic resonance imaging.

METHODS

The study included 350 patients with LDH and a minimum of 3 years of follow-up. Patients underwent microdiscectomy for LDH at the L4-L5 and L5-S1 levels from 2008 to 2012. Patients were divided into two groups to identify predictors of recurrence: those who developed rLDH (n=50) within 3 years and those who did not develop rLDH (n=300) within the same follow-up period. Multivariate analysis was performed using patient baseline clinical and radiography data. Non-linear, multivariate, logistic regression analysis was used to build a predictive model.

RESULTS

Recurrence of LDH occurred within 1 to 48 months after microdiscectomy. Preoperatively, patients who developed rLDH were smokers (70% vs. 27%, p<.01; odds ratio [OR]=6.31, 95% confidence interval [CI]: 3.27-12.16) and had higher body mass index (29.0±6.1 vs. 27.0±4.3, p=.03; OR=1.09 per 0.01 unit change). Radiological parameters that were associated with rLDH were higher disc height index (0.35±0.007 vs. 0.26±0.002, p<.001), higher segmental range of motion (9.8±0.28° vs. 7.6±0.11°, p<.001; OR=0.53 per 0.01 unit change), and lower central angle of lumbar lordosis (33.4±0.81° vs. 47.1±0.47°, p<.001; OR=0.53 per 0.01 unit change). Additionally, Pfirrmann grade 3 (OR=16.62, 95% CI: 8.10-34.11), protrusion type of LDH (OR=5.90, 95% CI: 3.06-11.36), and Grogan sclerosis grades 3 and 4 (OR=4.81, 95% CI: 2.50-9.22) were also associated with rLDH. Multivariate non-linear modeling allowed for more accurate prediction of rLDH (90% correct prediction of rLDH; 99% correct prediction of no rLDH) than other univariate logit models.

CONCLUSIONS

Preoperative radiographic parameters in patients with LDH can be used to assess the risk of recurrence after microdiscectomy. The multifactorial non-linear model provided more accurate rLDH probability estimation than the univariate analyses. The software developed from this model may be implemented during patient counseling or decision making when choosing the type of primary surgery for LDH.

Mechanistic insight into the effects of Aryl Hydrocarbon Receptor activation on osteogenic differentiation

While inhibition of bone healing and increased rates of pseudarthrosis are known adverse outcomes associated with cigarette smoking, the underlying mechanisms by which this occurs are not well understood. Recent work has implicated the Aryl Hydrocarbon Receptor (Ahr) as one mediator of the anti-osteogenic effects of cigarette smoke (CS), which contains numerous toxic ligands for the Ahr. 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, dioxin) is a high-affinity Ahr ligand frequently used to evaluate Ahr pathway activation. The purpose of this study was to elucidate the downstream mechanisms of dioxin action on bone regeneration and investigate Ahr antagonism as a potential therapeutic approach to mitigate the effects of dioxin on bone. Markers of osteogenic activity and differentiation were assessed in primary rat bone marrow stromal cells (BMSC) after exposure to dioxin, Ahr antagonists, or antagonist + dioxin. Four Ahr antagonists were evaluated: α-Naphthoflavone (ANF), resveratrol (Res), 3,3′-Diindolylmethane (DIM), and luteolin (Lut). Our results demonstrate that dioxin inhibited ALP activity, migratory capacity, and matrix mineralization, whereas co-treatment with each of the antagonists mitigated these effects. Dioxin also inhibited BMSC chemotaxis, while co-treatment with several antagonists partially rescued this effect. RNA and protein expression studies found that dioxin down-regulated numerous pro-osteogenic targets, whereas co-treatment with Ahr antagonists prevented these dioxin-induced expression changes to varying degrees. Our results suggest that dioxin adversely affects bone regeneration in a myriad of ways, many of which appear to be mediated by the Ahr. Our work suggests that the Ahr should be investigated as a therapeutic target to combat the adverse effects of CS on bone healing.

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Dioxin, a potent Ahr ligand, inhibits osteogenic differentiation of BMSC.

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“Nutraceutical” Ahr antagonists found in red wine and broccoli protected against dioxin action.

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Targets of dioxin action included Collagens, MMPs, Phex, CXCR4/CXCL12 axis.

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The Ahr may in part mediate the adverse effects of cigarette smoke on osteogenic differentiation and bone healing.

Smoking cessation advice in limb reconstruction: An opportunity not to be missed

The adverse health effects of smoking are well known, including its effects on the musculoskeletal system. Limb reconstruction using external fixators is a high intensity process with high levels of patient contact time, complications and cost. The aim of this study was to examine smoking patterns in this group and in particular to assess trends in smoking cession. Data was collected from 41 patients all undergoing treatment using circular frame external fixation, for a variety of pathologies, most commonly acute tibial trauma. A patient reported questionnaire was used. Data was collected over a six-month period. In our population 56.1% of patients were smokers. During the study 47.8% patients stopped smoking and a further 39.1% decreased their smoking behaviour. 78.3% of patients could recall being given smoking cessation advice. In our group, 87% of patients were unaware of the effects of smoking on bone healing. Once made aware during discussion of proposed treatment, 73.9% stated that it was, in part, this knowledge that prompted them to positively change their smoking habits. The results of this study show that advice regarding smoking cessation during limb reconstruction treatment can potentially have a positive impact on patients smoking habits. The effect of smoking should be linked to the patient pathology and discussed during the consent process. Taking the time with the patient for this simple free intervention can have a positive impact on patient health, and potentially on the outcome of their current treatment, and is an opportunity not to be missed.

The Nuclear Receptor AhR Controls Bone Homeostasis by Regulating Osteoclast Differentiation via the RANK/c-Fos Signaling Axis

The aryl hydrocarbon receptor (AhR) pathway plays a key role in receptor activator of NF-κB ligand (RANKL)-mediated osteoclastogenesis. However, the mechanism underlying the regulation of AhR expression in osteoclasts and the signaling pathway through which AhR controls osteoclastogenesis remain unclear. We found that the expression of AhR in bone marrow-derived osteoclasts was upregulated by RANKL at an earlier stage than was the expression of signature osteoclast genes such as those encoding cathepsin K and NFAT, cytoplasmic, calcineurin-dependent 1. In response to RANKL, bone marrow macrophages isolated from AhR^-/- mice exhibited impaired phosphorylation of Akt and MAPK as well as NF-κB, whereas their response to M-CSF remained unchanged. Osteoclast differentiation mediated by the AhR signaling pathway was also regulated in an RANKL/c-Fos-dependent manner. Furthermore, ligand activation of AhR by the smoke toxin benzo[a]pyrene accelerated osteoclast differentiation in a receptor-dependent manner, and AhR-dependent regulation of mitochondrial biogenesis in osteoclasts was observed. Moreover, AhR^-/- mice exhibited impaired bone healing with delayed endochondral ossification. Taken together, the present results suggest that the RANKL/AhR/c-Fos signaling axis plays a critical role in osteoclastogenesis, thereby identifying the potential of AhR in treating pathological, inflammatory, or metabolic disorders of the bone.

Effects of nicotine in the presence and absence of vitamin E on morphology, viability and osteogenic gene expression in MG-63 osteoblast-like cells

BACKGROUND

Evidence shows that oxidative stress induced by nicotine plays an important role in bone loss. Vitamin E with its antioxidative properties may be able to reverse the effects of nicotine on bone. This study aimed to assess the effects of nicotine in the presence and absence of vitamin E on morphology, viability and osteogenic gene expression in MG-63 (osteosarcoma) human osteoblast-like cells.

METHODS

We treated the cells with 5 mM nicotine. The viability and morphology of cells were evaluated respectively using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium (MTT) and crystal violet assays. The effect of nicotine on osteogenic gene expression in MG-63 cells was assessed by real-time reverse-transcription polymerase chain reaction of osteoblast markers, namely, alkaline phosphatase, osteocalcin and bone sialoprotein.

RESULTS

The results revealed that survival and proliferation of MG-63 cells were suppressed following exposure to nicotine, and cytoplasm vacuolization occurred in the cells. Nicotine significantly down-regulated the expression of osteogenic marker genes. Such adverse effects on morphology, viability and osteogenic gene expression of MG-63 cells were reversed by vitamin E therapy.

CONCLUSIONS

In conclusion, vitamin E supplementation may play a role in proliferation and differentiation of osteoblasts, and vitamin E can be considered as an anabolic agent to treat nicotine-induced bone loss.

The effect of smoking on ACL reconstruction: a systematic review

OBJECTIVE

Anterior cruciate ligament reconstruction (ACLR) depends on proper healing of the graft or bone plug at the cellular level. The effect of cigarette smoke on ACLR was not commonly reported until recently. The primary purpose of this review was to determine if smoking has a negative effect on subjective or objective outcome scores after ACLR. The secondary purpose was to identify any increased risk of complications, infection, ACL re-tear, or revision procedures.

METHODS

A systematic literature review of the MEDLINE, SCOPUS and PubMed databases was performed to identify all studies that compared outcomes of ACLR surgery between smokers and nonsmokers. The frequency-weighted mean was calculated for outcome measures that were similar across several studies.

RESULTS

Seventeen studies were identified that met inclusion criteria for patients undergoing ACLR (mean age, 26.8 years) with a mean follow-up of 37 months. Smokers had significantly worse subjective outcome measures and worse side-to-side difference in anterior translation compared to non-smokers (2.68 mm vs 1.89 mm, respectively). In 2 studies, smokers were found to have a significantly higher risk of developing an infection and VTE (venous thromboembolism) post-operatively. The evidence for the effect of smoking on risk for subsequent re-tear is mixed. No study reported a higher rate of development of radiographic knee osteoarthritis among smokers compared to nonsmokers.

CONCLUSIONS

Cigarette smoke is associated with significantly worse clinical outcome scores, an increase in anterior translation, and increased complication rates after ACL reconstruction. These findings may help orthopaedic surgeons better inform their patients about the potential negative effects of smoking on the outcomes of ACL reconstruction.

LEVEL OF EVIDENCE

Therapeutic Level IV.

Modifying Risk Factors for Total Joint Arthroplasty: Strategies That Work Nicotine

Smoking and nicotine use remain a major health care crisis in the United States. Although rates have dropped dramatically over the last 50 years, approximately 18% of the US adult population still smokes. The musculoskeletal effects of nicotine and other byproducts of smoking place patients at increased risk for perioperative complications including medical complication, wound healing problems, infection, and death. A comprehensive behavioral modification program with or without the use of nicotine replacement therapy has been shown to be most effective at smoking cessation around the time of planned surgery. Although literature suggests that smoking cessation 4-6 weeks before surgery can diminish risk, both current and former smokers are at increased risk for perioperative complications compared with those that have never smoked. Cotinine, a metabolite of nicotine, can be used to monitor smoking cessation before surgery.