Bundled Payments for Care Improvement: Boom or Bust?

BACKGROUND: As early implementors of the Centers for Medicare and Medicaid Services (CMS) Bundled Payments for Care Improvement (BPCI) initiative, our private practice sought to compare our readmission rates, post-acute care utilization, and length of stay for the first year under BPCI compared to baseline data. METHODS: We used CMS data to compare total expenditures of all diagnosis-related groups (DRGs). Medicare patients who underwent orthopedic surgery between 2009 and 2012 were defined as non-BPCI (n = 8415) and were compared to Medicare BPCI patients (n = 4757) who had surgery in 2015. Ninety-day post-acute events including inpatient rehabilitation facility or subacute nursing facility admission, home health (HH), and readmissions were analyzed. RESULTS: The median expenditure for non-BPCI patients was $22,193 compared to $19,476 for BPCI patients (P < .001). Median post-acute care spend was $6861 for non-BPCI and $5360 for BPCI patients (P < .001). Compared to non-BPCI patients, BPCI patients had a lower rate of subacute nursing facility admissions (non-BPCI 43% vs 37% BPCI; P < .001), inpatient rehabilitation facility admissions (non-BPCI 3% vs 4% BPCI; P = .005), HH (non-BPCI 79% vs 73% BPCI; P < .001), and readmissions (non-BPCI 12% vs 10% BPCI; P = .02). Changes in length of stay for post-acute care were only significant for HH with BPCI patients using a median 12 days and non-BPCI using 24 days. CONCLUSION: The objective of BPCI was to improve healthcare value. Through substantial efforts both financially and utilization of human resources to contain costs with clinical practice guidelines, patient navigators, and a BPCI management team, the expenditures for CMS were significantly lower for BPCI patients.

Stem geometry changes initial femoral fixation stability of a revised press-fit hip prosthesis: A finite element study.

BACKGROUND: Stable femoral fixation during uncemented total hip arthroplasty is critical to allow for subsequent osseointegration of the prosthesis. Varying stem designs provide surgeons with multiple options to gain femoral fixation. OBJECTIVE: The purpose of this study was to compare the initial fixation stability of cylindrical and tapered stem implants using two different underreaming techniques (press-fit conditions) for revision total hip arthroplasty (THA). METHODS: A finite element femur model was created from three-dimensional computed tomography images simulating a trabecular bone defect commonly observed in revision THA. Two 18-mm generic femoral hip implants were modeled using the same geometry, differing only in that one had a cylindrical stem and the other had a 2 degree tapered stem. Surgery was simulated using a 0.05-mm and 0.01-mm press-fit and tested with a physiologically relevant loading protocol. RESULTS: Mean contact pressure was influenced more by the surgical technique than by the stem geometry. The 0.05-mm press-fit condition resulted in the highest contact pressures for both the cylindrical (27.35 MPa) and tapered (20.99 MPa) stems. Changing the press-fit to 0.01-mm greatly decreased the contact pressure by 79.8% and 78.5% for the cylindrical (5.53 MPa) and tapered (4.52 MPa) models, respectively. The cylindrical stem geometry consistently showed less relative micromotion at all the cross-sections sampled as compared to the tapered stem regardless of press-fit condition. CONCLUSIONS: This finite element analysis study demonstrates that tapered stem results in lower average contact pressure and greater micromotion at the implant-bone interface than a cylindrical stem geometry. More studies are needed to establish how these different stem geometries perform in such non-ideal conditions encountered in revision THA cases where less bone stock is available.

Tapered vs Cylindrical Stem Fixation in a Model of Femoral Bone Deficiency in Revision Total Hip Arthroplasty.

BACKGROUND: Distal fixation achieved with a tapered stem design has demonstrated favorable clinical results in revision total hip arthroplasty in the setting of severe bone defects. However, stem subsidence is common with this stem design. PURPOSE: The purpose of this study is to compare the initial fixation stability of a tapered stem design to a fully porous-coated cylindrical stem design in a model of severe femoral bone deficiency. METHODS: Tapered and cylindrical stems (n = 8) were implanted into a model femur with progressively shorter segments for fixation (9, 6, or 3 cm). The stems were axially loaded, and the force to produce subsidence was recorded. RESULTS: Average loads to produce 150 µm of displacement with a 3-cm segment were higher for the tapered stem (393 N vs 221 N, P < .01). No difference was observed in the 6- or 9-cm models. Average loads to produce failure (>4-mm subsidence) were also higher for tapered stems with a 3-cm segment (1574 N vs 500 N, P < .0001). A regression analysis determined the minimum segment length of 1.5-2.5 cm to obtain stable fixation with a tapered stem design (R(2) = 0.78, P < .001). CONCLUSIONS: Tapered stems required higher loads to produce subsidence than cylindrical stems in a revision THA model. Revision tapered stems require a minimum intact segment of 1.5-2.5 cm to obtain adequate initial fixation stability. Revision tapered stems have superior initial fixation stability to cylindrical stems in the setting of severe bone loss.

Structural integrity after rotator cuff repair does not correlate with patient function and pain: a meta-analysis.

BACKGROUND: The correlation between the structural integrity of rotator cuff repair and the clinical outcome for the patient remains controversial. The purpose of this study was to assess the relationship between patient function and structural integrity of the rotator cuff after repair. METHODS: A systematic review and a meta-analysis were conducted for Level-I and Level-II studies showing outcome measures after rotator cuff repair and an imaging assessment of the structural integrity of the repair. Data extracted included patient demographics, tear size, repair type, clinical outcome measures, and repair integrity. Statistical analysis was performed to compare outcomes in patients on the basis of the structural integrity of repair at the time of the latest follow-up. RESULTS: Fourteen studies met inclusion criteria and were included in the latest analysis. Of the 861 patients who underwent rotator cuff repair with a minimum of a one-year follow-up, 674 patients (78.3%) had intact repairs at the time of latest follow-up. There was no difference in tear size between patients with intact repairs and those with retears (p = 0.866). The University of California Los Angeles shoulder score, the Constant score, and the American Shoulder and Elbow Surgeons score increased and the visual analog scale score decreased in patients regardless of the structural integrity of the repair. Patients with intact repairs had higher Constant scores by 8.93 points (p < 0.0001) and higher University of California Los Angeles shoulder scores by 2.95 points (p = 0.0004). Postoperative American Shoulder and Elbow Surgeons scores were no different in patients with intact repairs or retears (p = 0.15). Postoperative visual analog scale scores were 0.93 points lower in patients with intact repairs (p = 0.01). Patients with intact repairs had increased strength in forward elevation by 2.40 kilograms (5.29 pounds) (p < 0.00001) and had a trend toward increased strength in shoulder external rotation (p = 0.06). Although these results are significant, the differences are not clinically important on the basis of the validation of these outcome measures. CONCLUSIONS: The results of this study suggest that there is not a clinically important difference in validated functional outcome scores or pain for patients who have undergone rotator cuff repair regardless of the structural integrity of the repair. Patients with intact repairs do have significantly greater strength than those with retears.

Preoperative flexion does not influence postoperative flexion after rotating-platform total knee arthroplasty.

PURPOSE: Preoperative range of motion (ROM) has been regarded as one of the most important factors in predicting postoperative ROM following total knee arthroplasty (TKA). Mobile-bearing TKA designs have been suggested to possibly improve the knee kinematics compared to fixed-bearing designs. The purpose of this study was to examine the difference in postoperative flexion as a function of preoperative flexion in a consecutive series of TKAs done using a posterior-stabilized rotating-platform prosthesis. METHODS: ROM was assessed in 153 consecutive TKAs done using a rotating-platform posterior cruciate-substituting design. Patients were divided into two groups based on their preoperative ROM (Group 1 < 95°, Group 2 > 95°). The Knee Society Score (KSS) and ROM were assessed preoperatively, 3 months and 12 months postoperatively. RESULTS: There was no difference in flexion 12 months after surgery between groups (mean 120° and 123°, respectively. n.s.). After 3 month follow-up, no increase in ROM was experienced by either group. Patients in Group 1 experienced significantly greater increases in both ROM (p < 0.001) and KSS (p < 0.05). There was no difference in the KSS at 12 months after surgery between groups. CONCLUSION: In this series of patients undergoing TKA with a rotating-platform prosthesis, the preoperative ROM was not predictive of the postoperative ROM. Patients with stiff knees preoperatively may benefit from a mobile-bearing design prosthesis.

Impact of tunnels and tenodesis screws on clavicle fracture: a biomechanical study of varying coracoclavicular ligament reconstruction techniques.

PURPOSE: The purpose of this study was to compare the load to fracture of distal clavicles with no tunnels, one tunnel, or 2 tunnels and to evaluate the effect of inserting tenodesis screws in the tunnels on load to fracture of the distal clavicle. METHODS: Fifty right sawbone clavicles were obtained and divided into 5 groups (n = 10): group 1, normal clavicle; group 2, one tunnel, no tenodesis screw; group 3, 2 tunnels, no tenodesis screws; group 4, one tunnel with tenodesis screw; and group 5, 2 tunnels with 2 tenodesis screws. Tunnels were created using a 5-mm-diameter reamer, and 5.5 × 10 mm polyethyl ethyl ketone tenodesis screws were used. A 4-point bending load was applied to the distal clavicles. Load to failure was noted for each specimen. RESULTS: Load to failure in clavicles without tunnels was significantly higher (1,157.18 ± 147.10 N) than in all other groups (P < .0005). No statistical differences were noted between groups 2, 3, 4, and 5. Load to failure was not statistically different in clavicles with one versus 2 tunnels. In addition, the use of tenodesis screws in the tunnels did not affect the load required to fracture. CONCLUSIONS: The use of tunnels in the clavicle for coracoclavicular (CC) ligament reconstruction significantly reduces the load required to fracture the distal clavicle. The addition of tenodesis screws does not appear to significantly increase the strength of the clavicle in this construct. CLINICAL RELEVANCE: CC ligament reconstruction techniques commonly use tunnels in the distal clavicle, which may render the clavicle more susceptible to fracture. This study helps quantify the effect of these tunnels on the strength of the distal clavicle.

Beyond the peak of the anterior glenoid rim: A cadaveric study.

PURPOSE: The purpose of this study was to quantify the width of bone beyond the peak of the anterior glenoid rim and to determine if this anatomic region of the glenoid significantly affects measurement of the anteroposterior glenoid diameter. MATERIALS AND METHODS: 19 cadaveric scapulae were examined and the width of bone beyond the peak of the anterior glenoid rim was measured. The percent width of this region relative to the anteroposterior diameter of the glenoid was evaluated. Male and female specimens were compared. Measurements of the anteroposterior diameter of the glenoid, both including and excluding this region, were compared. RESULTS: The mean width of bone beyond the peak of the anterior glenoid rim was 3.2 ± 0.7 mm, corresponding to 10.5% of the anteroposterior glenoid diameter. This anatomic region is of similar relative size in males and females (11% vs 10% of the glenoid diameter). Measurement of the anteroposterior diameter of the glenoid is significantly different depending on whether this region is included or not (P = 0.0064). CONCLUSIONS: There exists a portion of the anterior glenoid that is beyond the peak of the anterior rim, and is not part of the concave articular surface. The width of this anatomic area comprises a significant percent of the anteroposterior glenoid diameter, and should be understood when quantifying and describing anterior glenoid bone loss in cases of glenohumeral instability. CLINICAL RELEVANCE: Understanding of anterior glenoid anatomy is important in the evaluation of glenohumeral instability. The portion of glenoid bone beyond the anterior rim peak is likely important for its soft tissue attachments, but its contribution to bony stability may be misunderstood.

Area-based determination of bone loss using the glenoid arc angle.

In patients with anterior glenohumeral instability, the most commonly observed osseous defect involves the anterior portion of the inferior glenoid. The amount of glenoid bone loss guides surgical treatment, with progressively larger defects not being amenable to arthroscopic soft-tissue procedures. Currently, there is no universally accepted method of quantifying glenoid bone loss. Two-dimensional area-based methods and 1-dimensional methods of measuring bone loss have both been described but cannot be used interchangeably. The surface area of a glenoid bony defect is a more comprehensive descriptor of its magnitude than the 1-dimensional width of the defect. Calculating surface area can be challenging. We describe a method of quantifying glenoid bone loss using a glenoid arc angle that corresponds to the surface area of the defect. The arc angle is easily measured by use of commonly used imaging software tools and is independent of the size of the glenoid or defect orientation. This method may prove valuable in preoperative planning for patients with anterior glenohumeral instability.

Does an enhanced surface finish improve acetabular fixation in revision total hip arthroplasty?

High-porosity "cancellous metal" coatings have been introduced to increase the fixation and biologic incorporation of acetabular cups. The strength of initial fixation provided by a cancellous metal cups vs conventional alternatives in the deficient revision acetabulum was investigated. Cancellous, plasma-sprayed, and beaded cups (n = 9) were implanted under controlled conditions into a validated model of the revision acetabulum. The greatest differences were seen in resistance to catastrophic (spin-out) failure that, for the cancellous shell, averaged 1076 ± 265 N, which was 25% greater than the plasma-sprayed implant (859 ± 214 N, P = .04) and 218% greater than the beaded implant (338 ± 123 N, P < .01). The cancellous coating also provided greater resistance to ultimate failure. These results suggest that these new cancellous metal coatings may represent a promising alternative for fixation in revision total hip arthroplasty.

Vesicoacetabular fistula in a chronically infected total hip arthroplasty.

Fistula formation between the bladder and acetabulum related to total hip arthroplasty (THA) is rare, and few cases have been documented. Common features of the reported cases include a defect in the medial wall of the acetabulum, a chronically infected THA, a history of bladder injury, vesicocutaneous fistulas, and a history of pelvis radiation exposure. We report the case of a vesicoacetabular fistula discovered during antibiotic spacer placement in a woman with a chronically infected THA. The patient received bilateral ureteral stents extending from the renal pelvis to the urethra. Three months later, the patient was free of infection and was able to undergo reimplantation arthroplasty.

Initial results of managing severe bone loss in infected total joint arthroplasty using customized articulating spacers.

Twenty-three cases of infected total joint arthroplasty with substantial bone loss were treated with a cement spacer, which was customized intraoperatively to achieve joint stability and to allow motion. All but one of the patients were ambulatory with the spacer in place. Spacer dislocation occurred in 1 hip patient (9%) and in none of the knee patients. Articulating antibiotic-impregnated spacers with intraoperative customization is our preferred treatment of cases of infected total joint arthroplasty even in the presence of bone loss.