ABSTRACT
BACKGROUND: Interscalene blocks provide analgesia for shoulder surgery but also cause phrenic nerve paralysis. Liposomal bupivacaine is approved for use in interscalene blocks with the potential to provide longer pain control. However, the impact of liposomal bupivacaine on the phrenic nerve has not been evaluated. It was hypothesized that patients who received an interscalene block with both bupivacaine and liposomal bupivacaine would have a decreased diaphragmatic excursion when compared to bupivacaine alone at 24 h. METHODS: This was a double-blinded study of adult patients who were randomized to receive an interscalene block with either 20 ml 0.5% bupivacaine (bupivacaine group) or 10 ml 0.5% bupivacaine plus 10 ml liposomal bupivacaine (liposomal bupivacaine group). Twenty-six patients were randomized with 22 included in the analysis. Diaphragmatic excursion (via ultrasound) and spirometry were assessed before the block, in the postanesthesia care unit, and at 24 h postblock. The primary outcome was diaphragm excursion with sigh. No adverse events were observed. RESULTS: At 24 h, the liposomal bupivacaine group median [25th, 75th], had a greater percent change in diaphragmatic excursion during sigh breath compared to the bupivacaine group, -24% [-30, -9] versus 9% [-8, 26], difference in location, 32 (95% CI, 12 to 52), P = 0.007. Five patients in the liposomal bupivacaine group had a greater than 25% reduction in diaphragmatic excursion at 24 h versus zero in the bupivacaine group. They also had a significantly greater percent reduction in forced expiratory volume in 1 s and forced vital capacity compared with the bupivacaine group at 24 h (median decrease of 22% vs. 2%, P = 0.006, and median decrease of 19% vs. 1%, P = 0.049, respectively). CONCLUSIONS: The addition of liposomal bupivacaine to bupivacaine in an interscalene block results in statistically significant reductions in diaphragm excursion and pulmonary function testing 24 h after block placement when compared to bupivacaine alone. This reduction, however, falls within the range of normal diaphragmatic function.
Subject(s)
Anesthetics, Local , Brachial Plexus Block , Adult , Brachial Plexus Block/methods , Bupivacaine , Diaphragm/diagnostic imaging , Humans , Pain, PostoperativeABSTRACT
PURPOSE OF REVIEW: A successful reverse total shoulder arthroplasty requires careful preoperative planning and perioperative management. Preoperative comorbidity risks, perioperative pain management, and postoperative rehabilitation are all critical components of this arthroplasty. The current review examines available literature to guide the perioperative care of the reverse total shoulder arthroplasty patient. RECENT FINDINGS: One of the most important advances for shoulder arthroplasty in recent years has been heightened awareness of various modalities for perioperative pain management. A number of recent studies have focused on the options for regional blockade as a critical tool for postoperative pain relief and the use of either continuous interscalene blocks or single shot blocks are supported. Additional studies are necessary to define the best local anesthetic agent and delivery mechanism to provide appropriate pain relief with a low side effect profile. Management of the patient throughout the perioperative course is a critical component in achieving better patient outcomes delivering high quality patient care. An orthopedic surgery team focused on perioperative management is better positioned to decrease adverse events and improve patient outcomes after reverse total shoulder arthroplasty.
ABSTRACT
BACKGROUND: The optimal surgical approach for recurrent anterior shoulder instability remains controversial, particularly in the face of glenoid and/or humeral bone loss. The purpose of this study was to use a contingent-behavior questionnaire (CBQ) to determine which factors drive surgeons to perform bony procedures over soft tissue procedures to address recurrent anterior shoulder instability. METHODS: A CBQ survey presented each respondent with 32 clinical vignettes of recurrent shoulder instability that contained 8 patient factors. The factors included (1) age, (2) sex, (3) hand dominance, (4) number of previous dislocations, (5) activity level, (6) generalized laxity, (7) glenoid bone loss, and (8) glenoid track. The survey was distributed to fellowship-trained surgeons in shoulder/elbow or sports medicine. Respondents were asked to recommend either a soft tissue or bone-based procedure, then specifically recommend a type of procedure. Responses were analyzed using a multinomial-logit regression model that quantified the relative importance of the patient characteristics in choosing bony procedures. RESULTS: Seventy orthopedic surgeons completed the survey, 33 were shoulder/elbow fellowship trained and 37 were sports medicine fellowship trained; 52% were in clinical practice ≥10 years and 48% <10 years; and 95% reported that the shoulder surgery made up at least 25% of their practice. There were 53% from private practice, 33% from academic medicine, and 14% in government settings. Amount of glenoid bone loss was the single most important factor driving surgeons to perform bony procedures over soft tissue procedures, followed by the patient age (19-25 years) and the patient activity level. The number of prior dislocations and glenoid track status did not have a strong influence on respondents' decision making. Twenty-one percent glenoid bone loss was the threshold of bone loss that influenced decision toward a bony procedure. If surgeons performed 10 or more open procedures per year, they were more likely to perform a bony procedure. CONCLUSION: The factors that drove surgeons to choose bony procedures were the amount of glenoid bone loss with the threshold at 21%, patient age, and their activity demands. Surprisingly, glenoid track status and the number of previous dislocations did not strongly influence surgical treatment decisions. Ten open shoulder procedures a year seems to provide a level of comfort to recommend bony treatment for shoulder instability.
Subject(s)
Joint Instability , Shoulder Dislocation , Shoulder Joint , Surgeons , Adult , Decision Making , Humans , Joint Instability/surgery , Shoulder , Shoulder Dislocation/surgery , Shoulder Joint/surgery , Young AdultABSTRACT
PURPOSE OF REVIEW: The incidence of shoulder arthroplasty is increasing dramatically for primary arthroplasty but also for revision arthroplasty. Revision to reverse total shoulder arthroplasty is increasingly the salvage operation for failed primary arthroplasty. The purpose of this review is to explore the indications for and results of revision reverse total shoulder arthroplasty. RECENT FINDINGS: Despite relatively high complication and reoperation rates with revision shoulder replacement, revision of failed hemiarthroplasty or total shoulder arthroplasty to reverse total shoulder arthroplasty improves outcomes for many patients. A failed hemiarthroplasty or total shoulder arthroplasty is frequently disabling for the patient and because the surgical revision options are often limited only to reverse total shoulder arthroplasty, the potential improvement is often worth the higher surgical complication or reoperation rate. Due to the challenges inherent in revision arthroplasty, revision of primary arthroplasty to reverse total shoulder arthroplasty, outcomes are poorer than primary reverse total shoulder arthroplasty. Despite these limitations, patient postoperative pain and function do increase from preoperative levels making conversion of hemiarthroplasty or anatomic total shoulder to reverse total shoulder arthroplasty an important option for a challenging problem.
ABSTRACT
Shoulder arthroplasty has traditionally been viewed as an inpatient procedure because of the inherent medical comorbidities associated with an aging population and the need for postoperative pain control. Recent studies have shown that in appropriately selected patients, shoulder arthroplasty procedures can be safely done as outpatient procedures and can deliver economic value in today's cost-conscious health care environment. Several factors help ensure a successful surgical outcome, including cooperation from the ambulatory anesthesia service, proper patient selection, and perioperative pain control. Postoperatively, provider availability is vital to complete a seamless patient experience. With appropriate algorithms and care plans in place, outpatient shoulder arthroplasty can be a safe and cost-efficient procedure. The advances pioneered by outpatient shoulder arthroplasty will also serve to benefit inpatient shoulder arthroplasty patients via improved pain control, perioperative education, and potentially decreased length of stay.
Subject(s)
Arthroplasty, Replacement, Shoulder , Aged , Ambulatory Surgical Procedures , Arthroplasty , Humans , Length of Stay , Outpatients , Patient SelectionABSTRACT
BACKGROUND: There have been conflicting results when comparing outcomes of open vs. arthroscopic anterosuperior rotator cuff repairs with subscapularis involvement. The purpose of this study was to evaluate midterm outcome differences and complications following open vs. arthroscopic repair of rotator cuff tears involving the subscapularis by a single surgeon. METHODS: This was a retrospective review of 57 rotator cuff repairs involving the subscapularis performed by a single surgeon over a 10-year period. During this time, the surgeon transitioned from open to arthroscopic repair. Preoperative and postoperative range of motion, lift-off test, belly press test, and American Shoulder and Elbow Surgeons (ASES) Standardized Shoulder Assessment form scores were measured. RESULTS: Eighteen patients had open procedures and 39 had arthroscopic repair. The mean preoperative ASES score for the open group was 39 and postoperatively was 79. The mean preoperative ASES score for the arthroscopic group was 44 and improved to 80 postoperatively. There was no significant difference in score or change in score between the 2 groups (P > .05). There was only 1 complication. It occurred in the open group and was a superficial wound dehiscence. CONCLUSIONS: This study demonstrated no outcome differences between open and arthroscopic rotator cuff repair involving the subscapularis, even with large subscapularis tears. Both techniques significantly improved shoulder function. Arthroscopic and open rotator cuff repairs including the subscapularis are relatively safe procedures, and either technique is an acceptable option.
Subject(s)
Arthroscopy/adverse effects , Postoperative Complications/epidemiology , Retrospective Studies , Rotator Cuff Injuries/pathology , Rotator Cuff Injuries/surgery , Adult , Aged , Female , Humans , Male , Middle Aged , Range of Motion, Articular , Recovery of Function , Shoulder Joint , Treatment OutcomeABSTRACT
"Impingement syndrome" is a common diagnostic label for patients presenting with shoulder pain. Historically, it was believed to be due to compression of the rotator cuff tendons beneath the acromion. It has become evident that "impingement syndrome" is not likely an isolated condition that can be easily diagnosed with clinical tests or most successfully treated surgically. Rather, it is likely a complex of conditions involving a combination of intrinsic and extrinsic factors. A mechanical impingement phenomenon as an etiologic mechanism of rotator cuff disease may be distinct from the broad diagnostic label of "impingement syndrome". Acknowledging the concepts of mechanical impingement and movement-related impairments may better suit the diagnostic and interventional continuum as they support the existence of potentially modifiable impairments within the conservative treatment paradigm. Therefore, it is advocated that the clinical diagnosis of "impingement syndrome" be eliminated as it is no more informative than the diagnosis of "anterior shoulder pain". While both terms are ambiguous, the latter is less likely to presume an anatomical tissue pathology that may be difficult to isolate either with a clinical examination or with diagnostic imaging and may prevent potentially inappropriate surgical interventions. We further recommend investigation of mechanical impingement and movement patterns as potential mechanisms for the development of shoulder pain, but clearly distinguished from a clinical diagnostic label of "impingement syndrome". For shoulder researchers, we recommend investigations of homogenous patient groups with accurately defined specific pathologies, or with subgrouping or classification based on specific movement deviations. Diagnostic labels based on the movement system may allow more effective subgrouping of patients to guide treatment strategies.
Subject(s)
Shoulder Impingement Syndrome/diagnosis , Shoulder Impingement Syndrome/surgery , Humans , Orthopedics/methods , Physical Therapy Modalities , Rotator Cuff , Shoulder Impingement Syndrome/etiology , Shoulder Impingement Syndrome/therapy , TendonsABSTRACT
Cases of consecutive new patients seen at orthopedic spine and shoulder clinics were reviewed. Four percent of spine patients had significant shoulder pathology, and 3.6% of shoulder patients had significant spine pathology. Identification of the correct pain generator is a prerequisite for effective treatment in patients with neck and/or shoulder problems. However, distinguishing between the two can be difficult. Relative frequencies of how often one is mistaken for the other have not been well established. Six hundred ninety-four new patients were seen at the orthopedic shoulder clinic (n = 452) or spine clinic (n = 242) at an academic institution during a 2-year period. One hundred seven patients had previous shoulder surgery, and 39 had previous neck surgery. The 548 patients (shoulder clinic, 345; spine clinic, 203) who had no previous surgery were reviewed with respect to workup performed, final diagnosis, subsequent operative procedures, and incidence of referral from the shoulder clinic to the spine clinic and vice versa. Among the patients seen at the shoulder clinic, 325 (94.2%) had shoulder pathology, 6 (1.7%) had neck but no shoulder pathology, 6 (1.7%) had shoulder and neck pathology, and 8 (2.3%) had an unidentifiable cause of pain. Of the 12 patients with neck pathology, none underwent neck surgery. Among the patients seen at the spine clinic, 182 (89.7%) had neck pathology, 5 (2.5%) had shoulder but no neck pathology, 3 (1.5%) had neck and shoulder pathology, and 13 (6.4%) had an unidentifiable cause of pain. Of the 8 patients with shoulder pathology, 1 (12.5%) underwent shoulder surgery. Our analysis suggests that for patients who present to a shoulder surgeon's clinic for shoulder pain, 3.6% will turn out to have neck pathology. For patients who present to a spine surgeon's clinic for neck pain, 4% may turn out to have shoulder pathology. Thus, approximately 1 in 25 patients seen at a surgeon's clinic for a presumed shoulder or neck problem may exhibit neck-shoulder crossover, in which pathology in one may be mistaken for or coexist with the other.
Subject(s)
Neck Pain/diagnosis , Shoulder Pain/diagnosis , Adolescent , Adult , Aged , Aged, 80 and over , Child , Diagnosis, Differential , Female , Humans , Male , Middle Aged , Neck Pain/physiopathology , Neck Pain/surgery , Shoulder Pain/physiopathology , Shoulder Pain/surgeryABSTRACT
BACKGROUND: Mini-open reduction and percutaneous fixation of proximal humeral fractures historically results in good outcomes and a low prevalence of osteonecrosis reported with short-term follow-up. The purpose of this study was to determine the midterm results of our multicenter case series of proximal humeral fractures treated with percutaneous fixation. METHODS: Between 1999 and 2006, thirty-nine patients were treated with percutaneous reduction and fixation for proximal humeral fractures at three tertiary shoulder referral centers. Twenty-seven of these patients were available for intermediate follow-up at a minimum of three years (mean, eighty-four months; range, thirty-seven to 128 months) after surgery; the follow-up examination included use of subjective outcome measures and radiographic analysis to identify osteonecrosis and posttraumatic osteoarthritis on radiographs. RESULTS: Osteonecrosis was detected in seven (26%) of the total group of twenty-seven patients at a mean of fifty months (range, eleven to 101 months) after the date of percutaneous fixation. Osteonecrosis was observed in five (50%) of the ten patients who had four-part fractures, two (17%) of the twelve patients who had three-part fractures, and none (0%) of the five patients who had two-part fractures. Posttraumatic osteoarthritis, including osteonecrosis, was present on radiographs in ten (37%) of the total group of twenty-seven patients. Posttraumatic osteoarthritis was observed in six (60%) of the ten patients who had four-part fractures, four (33%) of the twelve patients who had three-part fractures, and none (0%) of the five patients who had two-part fractures. CONCLUSIONS: Intermediate follow-up of patients with percutaneously treated proximal humeral fractures demonstrates an increased prevalence of osteonecrosis and posttraumatic osteoarthritis over time, with some patients with these complications presenting as late as eight years postoperatively. Development of osteonecrosis did not have a universally negative impact on subjective outcome scores.
Subject(s)
Fracture Fixation/methods , Osteoarthritis/etiology , Osteonecrosis/etiology , Range of Motion, Articular/physiology , Shoulder Fractures/surgery , Adult , Aged , Bone Nails , Cohort Studies , Female , Follow-Up Studies , Fracture Fixation/adverse effects , Fracture Healing/physiology , Humans , Injury Severity Score , Male , Middle Aged , Minimally Invasive Surgical Procedures/adverse effects , Minimally Invasive Surgical Procedures/methods , Osteoarthritis/diagnostic imaging , Osteoarthritis/epidemiology , Osteonecrosis/diagnostic imaging , Osteonecrosis/epidemiology , Pain, Postoperative/physiopathology , Postoperative Complications/pathology , Postoperative Complications/surgery , Radiography , Reoperation , Retrospective Studies , Risk Assessment , Shoulder Fractures/diagnostic imaging , Time Factors , Treatment OutcomeABSTRACT
BACKGROUND: Recent publications suggest that arthroscopic and open rotator cuff repairs have had comparable clinical results, although each technique has distinct advantages and disadvantages. National hospital and ambulatory surgery databases were reviewed to identify practice patterns for rotator cuff repair. METHODS: The rates of medical visits for rotator cuff pathology, and the rates of open and arthroscopic rotator cuff repair, were examined for the years 1996 and 2006 in the United States. The national incidence of rotator cuff repairs and related data were obtained from inpatient (National Hospital Discharge Survey, NHDS) and ambulatory surgery (National Survey of Ambulatory Surgery, NSAS) databases. These databases were queried with use of International Classification of Diseases, Ninth Revision (ICD-9) procedure codes for arthroscopic (ICD-9 codes 83.63 and 80.21) and open (code 83.63 without code 80.21) rotator cuff repair. We also examined where the surgery was performed (inpatient versus ambulatory surgery center) and characteristics of the patients, including age, sex, and comorbidities. RESULTS: The unadjusted volume of all rotator cuff repairs increased 141% in the decade from 1996 to 2006. The unadjusted number of arthroscopic procedures increased by 600% while open repairs increased by only 34% during this time interval. There was a significant shift from inpatient to outpatient surgery (p < 0.001). CONCLUSIONS: The increase in national rates of rotator cuff repair over the last decade has been dramatic, particularly for arthroscopic assisted repair.
Subject(s)
Rotator Cuff/surgery , Adult , Aged , Aged, 80 and over , Arthroscopy/statistics & numerical data , Arthroscopy/trends , Female , Health Care Surveys , Humans , Male , Middle Aged , Orthopedic Procedures/statistics & numerical data , Orthopedic Procedures/trends , Rotator Cuff Injuries , United StatesABSTRACT
Subacromial impingement syndrome (SIS) represents a spectrum of pathology ranging from subacromial bursitis to rotator cuff tendinopathy and full-thickness rotator cuff tears. The relationship between subacromial impingement and rotator cuff disease in the etiology of rotator cuff injury is a matter of debate. Both extrinsic compression and intrinsic degeneration may play a role. Management includes physical therapy, injections, and, for some patients, surgery. There remains a need for high-quality studies of the pathology, etiology, and management of SIS.
Subject(s)
Shoulder Impingement Syndrome/therapy , Debridement , Glucocorticoids/administration & dosage , Humans , Injections, Intra-Articular , Magnetic Resonance Imaging , Physical Examination , Shoulder Impingement Syndrome/diagnosis , Shoulder Impingement Syndrome/etiology , Shoulder Impingement Syndrome/pathology , Shoulder Pain/etiology , Treatment OutcomeABSTRACT
BACKGROUND: Management of the cuff-deficient arthritic shoulder has long been challenging. Early unconstrained shoulder arthroplasty systems were associated with high complication and implant failure rates. The evolution toward the modern reverse shoulder arthroplasty includes many variables of constrained shoulder arthroplasty designs. QUESTIONS/PURPOSES: This review explores the development of reverse shoulder arthroplasty, specifically describing (1) the evolution of reverse shoulder arthroplasty designs, (2) the biomechanical variations in the evolution of this arthroplasty, and (3) the current issues relevant to reverse shoulder arthroplasty today. METHODS: Using a PubMed search, the literature was explored for articles addressing reverse shoulder arthroplasty, focusing on those papers with historical context. RESULTS: Results of the early designs were apparently poor, although they were not subjected to rigorous clinical research and usually reported only in secondary literature. We identified a trend of glenoid component failure in the early reverse designs. This trend was recognized and reported by authors as the reverse shoulder evolved. Authors reported greater pain relief and better function in reverse shoulder arthroplasty with the fundamental change of Grammont's design (moving the center of rotation medially and distally). However, current reports suggest lingering concerns and challenges with today's designs. CONCLUSIONS: The history of reverse shoulder arthroplasty involves the designs of many forward-thinking surgeons. Many of these highly constrained systems failed, although more recent designs have demonstrated improved longevity and implant performance. Reverse shoulder arthroplasty requires ongoing study, with challenges and controversies remaining around present-day designs.
Subject(s)
Arthritis/history , Arthroplasty, Replacement/history , Rotator Cuff , Shoulder Joint , Arthritis/diagnostic imaging , Arthritis/physiopathology , Arthritis/surgery , Arthroplasty, Replacement/instrumentation , Biomechanical Phenomena , History, 20th Century , Humans , Joint Prosthesis/history , Prosthesis Design , Radiography , Range of Motion, Articular , Recovery of Function , Rotator Cuff/diagnostic imaging , Rotator Cuff/physiopathology , Rotator Cuff/surgery , Shoulder Injuries , Shoulder Joint/diagnostic imaging , Shoulder Joint/physiopathology , Shoulder Joint/surgery , Treatment OutcomeABSTRACT
BACKGROUND: The best location for biceps tenodesis is controversial as surgeons have begun to question whether tenodesis location affects the incidence of residual bicipital postoperative pain. An open distal tenodesis technique has been previously proposed to eliminate remaining symptoms at the bicipital groove. QUESTIONS/PURPOSES: We asked the following questions: (1) Does a higher tenodesis in the biceps groove result in postoperative pain? And (2) can the tenodesis location be successfully moved more distally ("suprapectoral tenodesis") by an arthroscopic technique? METHODS: We retrospectively reviewed 17 patients undergoing arthroscopic biceps tenodesis and evaluated their tenodesis location, either within the upper half of the groove (five) or in the lower half of the groove or shaft (12). Patient outcomes were assessed with visual analog scale scores for pain, American Shoulder and Elbow Surgeons scores, and Constant-Murley scores. Minimum followup was 12 months (mean, 28 months; range, 12-69 months). RESULTS: Two patients had persistent pain at 12 months; both had a tenodesis in the upper half of the groove. The overall American Shoulder and Elbow Surgeons and Constant-Murley scores were improved at latest followup. CONCLUSIONS: Arthroscopic suprapectoral biceps tenodesis represents a new technique for distal tenodesis. Our preliminary observations suggest a more distal tenodesis location may decrease the incidence of persistent postoperative pain at the bicipital groove, although additional research is needed to definitively state whether the proximal location is in fact more painful. LEVEL OF EVIDENCE: Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.
Subject(s)
Arthroscopy , Pain, Postoperative/prevention & control , Tendon Injuries/surgery , Tenodesis/methods , Tenosynovitis/surgery , Arm , Arthroscopy/adverse effects , Humans , New York City , Pain Measurement , Pain, Postoperative/etiology , Radiography , Recovery of Function , Retrospective Studies , Tendon Injuries/diagnostic imaging , Tendon Injuries/physiopathology , Tenodesis/adverse effects , Tenosynovitis/diagnostic imaging , Tenosynovitis/physiopathology , Time Factors , Treatment OutcomeABSTRACT
HYPOTHESIS: Conservative rehabilitation after arthroscopic rotator cuff repair does not result in long-term stiffness and improves rates of tendon healing. MATERIALS AND METHODS: We retrospectively evaluated 43 patients with full-thickness rotator cuff tears who underwent a standardized, conservative protocol of full-time sling immobilization without formal therapy for 6 weeks after arthroscopic repair. At 6 to 8 weeks of follow-up, we categorized patients as "stiff" if they demonstrated forward elevation of less than 100° and external rotation of less than 30° passively; all others were designated "nonstiff." Active range of motion in forward elevation, external rotation, and internal rotation was assessed at 3 months, 6 months, and 1 year. American Shoulder and Elbow Surgeons (ASES) and Constant-Murley scores were assessed at 1 year. Follow-up magnetic resonance imaging (MRI) was obtained in all patients to assess tendon healing. RESULTS: Ten patients (23%) were considered stiff after rotator cuff surgery. At 1 year, there was no difference in mean forward elevation (166° vs 161°, P = .2), external rotation (62° vs. 58.4°, P = .5), or internal rotation (T7.4 vs T8.2, P = .07) between the stiff and nonstiff groups, respectively. There were no differences in final ASES (83 vs 79, P = .57) and Constant-Murley scores (77 vs. 74, P = .5). Repeat MRI suggested a trend toward a lower retear rate among the stiff patients (70% intact in stiff group vs 36% in nonstiff group, P = .079). Two clinically significant cuff retears occurred in the nonstiff cohort. DISCUSSION: Concerns for recalcitrant stiffness have led some to favor early postoperative therapy. We found that early restriction of motion did not lead to long-term stiffness after arthroscopic rotator cuff repair, even in patients who were clinically stiff in the early postoperative period. CONCLUSIONS: Sling immobilization for 6 weeks after arthroscopic rotator cuff repair does not result in increased long-term stiffness and may improve the rate of tendon healing.
Subject(s)
Arthroscopy/rehabilitation , Rotator Cuff Injuries , Rotator Cuff/surgery , Adult , Aged , Aged, 80 and over , Decompression, Surgical , Female , Humans , Male , Middle Aged , Pain Measurement , Range of Motion, Articular , Retrospective Studies , Rupture , Shoulder Joint/physiopathology , Tendinopathy/surgery , Time Factors , Treatment OutcomeABSTRACT
BACKGROUND: TKA with conventional metal-backed tibial implants subjects the tibial metaphysis to stress shielding, with resultant loss of bone density. QUESTIONS/PURPOSES: We hypothesized tibial bone mineral density in patients with porous tantalum (trabecular metal) tibial baseplates would (1) more closely parallel tibial bone mineral density in the nonoperative control limb and (2) be better maintained than in conventional historical controls. PATIENTS AND METHODS: We prospectively followed 41 patients (35 men, six women) 60 years of age or younger undergoing TKA with uncemented trabecular metal tibial components. Patients underwent dual-energy xray absorptiometry scans of both proximal tibiae preoperatively and at 2 months, 1 year, and 2 years postoperatively. We determined bone mineral density in three selected regions of interest (Zone 1, between the pegs; Zone 2, beneath the pegs; Zone 3, directly below entire baseplate). Precision analysis revealed a precision error of 4% or less for each region of interest, indicating adequate power to detect bone mineral density changes of 8% or greater. RESULTS: Bone mineral density percent change was different between the operative and nonoperative knees only in Zone 3 and only at 2 months. There was no change in bone mineral density in any zone in the nonoperative knee at any time. Only in Zone 3 did the bone mineral density decrease at 2 months in the operative knee. CONCLUSIONS: Trabecular metal implants appear to maintain tibial bone mineral density in a parallel fashion to the nonoperative limb in this population and better than historical controls.