Is the timing of fixation associated with fracture-related infection among tibial plateau fracture patients with compartment syndrome? A multicenter retrospective cohort study of 729 patients.

BACKGROUND: Tibial plateau fractures with an ipsilateral compartment syndrome are a clinical challenge with limited guidance regarding the best time to perform open reduction and internal fixation (ORIF) relative to fasciotomy wound closure. This study aimed to determine if the risk of fracture-related infection (FRI) differs based on the timing of tibial plateau ORIF relative to closure of ipsilateral fasciotomy wounds. METHODS: A retrospective cohort study identified patients with tibial plateau fractures and an ipsilateral compartment syndrome treated with 4-compartment fasciotomy at 22 US trauma centers from 2009 to 2019. The primary outcome measure was FRI requiring operative debridement after ORIF. The ORIF timing relative to fasciotomy closure was categorized as ORIF before, at the same time as, or after fasciotomy closure. Bayesian hierarchical regression models with a neutral prior were used to determine the association between timing of ORIF and infection. The posterior probability of treatment benefit for ORIF was also determined for the three timings of ORIF relative to fasciotomy closure. RESULTS: Of the 729 patients who underwent ORIF of their tibial plateau fracture, 143 (19.6%) subsequently developed a FRI requiring operative treatment. Patients sustaining infections were: 21.0% of those with ORIF before (43 of 205), 15.9% at the same time as (37 of 232), and 21.6% after fasciotomy wound closure (63 of 292). ORIF at the same time as fasciotomy closure demonstrated a 91% probability of being superior to before closure (RR, 0.75; 95% CrI, 0.38 to 1.10). ORIF after fasciotomy closure had a lower likelihood (45%) of a superior outcome than before closure (RR, 1.02; 95% CrI; 0.64 to 1.39). CONCLUSION: Data from this multicenter cohort confirms previous reports of a high FRI risk in patients with a tibial plateau fracture and ipsilateral compartment syndrome. Our results suggest that ORIF at the time of fasciotomy closure has the highest probability of treatment benefit, but that infection was common with all three timings of ORIF in this difficult clinical situation.

Screws-Only Primary Subtalar Arthrodesis for Calcaneus Fractures.

BACKGROUND: The management of displaced intraarticular calcaneus fractures (DIACFs) is a difficult problem with disappointing results from open reduction internal fixation (ORIF). Alternatively, ORIF with primary subtalar arthrodesis (PSTA) has gained increasing popularity. The purpose of this study is to review patient-centered and radiographic outcomes of ORIF plus PSTA using only screws through a sinus tarsi approach. METHODS: A retrospective study of patients who underwent ORIF+PSTA for DIACFs was conducted. The same surgical technique was used in all cases consisting of only screws; no plates were used. Delayed surgeries past 8 weeks were excluded. Demographic and radiographic data were collected including worker's compensation claims. Plain radiographs were used to characterize injuries and review outcomes. RESULTS: Seventy-nine DIACFs underwent PSTA with a median follow-up of 200 days (n = 69 patients). Median time to weightbearing was 57.5 days postoperatively. Ten fractures were documented as Sanders II, 36 as Sanders III, and 32 as Sanders IV. Sixty-eight fractures (86.1%) achieved fusion on radiographs at a median of 126.5 (range, 54-518) days. Thirty-nine fractures (57.3%) demonstrated radiographic fusion in all 3 predefined locations. Nine of the 14 worker's compensation patients returned to work within the period of observation. There were 8 complications: 3 requiring a secondary operation. Eleven of 79 fractures treated did not go on to achieve radiographic union. CONCLUSION: In this retrospective case series, we found that screws-only primary subtalar arthrodesis for the treatment of DIACFs through a sinus tarsi approach was associated with relatively high rates of return to work and radiographic fusion. LEVEL OF EVIDENCE: Level IV, retrospective case series.

Failure to Medically Optimize Before Total Hip Arthroplasty: Which Modifiable Risk Factor Is the Most Dangerous?

BACKGROUND: There is mounting evidence that smoking, abnormal body mass index (BMI), uncontrolled diabetes, and poor nutritional status are associated with complications after total hip arthroplasty (THA). The goal of the present study was to evaluate the consequences of failure to medically optimize Medicare-eligible patients with respect to these key modifiable health targets by assessing complications in the early postoperative period after THA. METHODS: The National Surgical Quality Improvement Program database was queried for all primary THAs performed in 2018. Data were collected on preoperative serum albumin, BMI, diabetes, and tobacco use as well as postoperative infections, readmissions, complications, and mortality. We identified 47,924 THA patients with a median BMI of 29 kg/m2 and age of 72 years, and 60% of whom were female. RESULTS: We found that preoperative albumin <3.5 g/dL, BMI ≥40 kg/m2, tobacco use, and diabetes were all individually associated with increased risk of postoperative complications. Serum albumin <3.5 g/dL was the greatest overall risk factor for infection (odds ratio [OR]: 3.1, 95% confidence interval [CI]: 2.3-4.4, P < .0001), readmission (OR: 2.2, 95% CI: 1.9-2.5, P < .0001), any complication (OR: 4.2, 95% CI: 3.8-4.6, P < .0001), and mortality (OR: 7.5, 95% CI: 5.3-10.6, P < .0001). CONCLUSIONS: Low albumin, elevated BMI, tobacco use, and diabetes are associated with increased risk of postoperative infection, readmission, any complication, and mortality after primary THA. Low albumin poses the greatest risk of these. Preoperative optimization should be obtained in all patients before elective surgery, and the final decision for surgery should be individually made between a surgeon and patient. LEVEL OF EVIDENCE: IV.

Wound Management in Total Knee Prosthetic Joint Infections.

Total knee arthroplasty complicated by periprosthetic joint infection can be devastating. Patients undergoing treatment for prosthetic joint infection have often undergone multiple surgeries and may have associated soft tissue defects that complicate treatment. These defects often require soft tissue reconstruction in order to cover the prosthesis. Coverage options range from simple tissue rearrangement to free flap reconstruction. A team approach between orthopaedic and plastic surgery is imperative to help retain the prosthesis and improve functional outcomes. (Journal of Surgical Orthopaedic Advances 30(4):196-201, 2021).

Prevention of Periprosthetic Joint Infection of the Hip and Knee: Modern Techniques and Strategies.

Prosthetic joint infection is a feared complication following elective total joint arthroplasty of the hip and knee. Infection following arthroplasty leads to high morbidity and even mortality and is a major burden to the health care system. Although many advances are being made in the treatment of prosthetic joint infection, with the increasing volume of total joint arthroplasty anticipated over the next decade, a significant emphasis should be placed on prevention. Several preoperative, intraoperative, and postoperative strategies may be employed to help reduce the risk. (Journal of Surgical Orthopaedic Advances 30(4):202-206, 2021).

Patient Optimization Strategies Prior to Elective Total Hip and Knee Arthroplasty.

Periprosthetic joint infection (PJI) following elective total hip and knee arthroplasty remains a devastating complication. PJI is associated with high morbidity and mortality to the patient as well as high expenses to the health care system. Although patient optimization prior to elective arthroplasty has gained notoriety and shown to help prevent complications, surgeons continue to operate on patients who are not optimized for surgery. Lack of optimization has been shown to lead to increased risk of complications and poor outcomes. The surgeon should be vigilant to correct modifiable risk factors prior to elective arthroplasty to help minimize the risk of PJI. (Journal of Surgical Orthopaedic Advances 30(4):207-211, 2021).

Comparative Outcomes of All-Inside Versus Inside-Out Repair of Bucket-Handle Meniscal Tears: A Propensity-Matched Analysis.

BACKGROUND: There are limited data comparing the outcomes of all-inside versus inside-out meniscal repair techniques. PURPOSE: To assess failure rates and clinical outcomes after the surgical repair of bucket-handle meniscal tears utilizing either an all-inside or inside-out technique. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Patients with bucket-handle meniscal tears undergoing all-inside or inside-out repair at a single institution between 2003 and 2013 were analyzed. A total of 28 mensici repaired utilizing second-generation all-inside suturing devices and 42 menisci repaired using an inside-out technique were eligible for inclusion. Rigorous propensity matching was performed on the basis of age, sex, tear laterality, rim width, and concomitant anterior cruciate ligament reconstruction (ACLR), resulting in a total of 40 patients equally distributed between the 2 repair techniques for comparison. Retear-free survival as well as preoperative and postoperative International Knee Documentation Committee (IKDC) and Tegner scores and physical examination findings were subsequently analyzed. RESULTS: Twenty patients who underwent all-inside repair (14 male; mean age, 23.7 ± 6.7 years) were successfully propensity matched to 20 patients who underwent inside-out meniscal repair (15 male; mean age, 22.5 ± 7.6 years), with a mean retear-free follow-up of 4.4 years (range, 2.5-7.4 years). Four (20%) all-inside repairs and 4 (20%) inside-out repairs failed over the course of follow-up (P > .999), with a mean time to failure of 2.7 years (range, 1.3-4.4 years) and 5.0 years (range, 0.8-7.5 years), respectively (P = .25). Increasing patient age trended toward a decreased clinical retear rate, independent of the repair technique (hazard ratio, 0.86; P = .056). There were no significant differences in the Tegner scores, IKDC scores, or range of motion between the groups as a whole or when subcategorizing by age, sex, body mass index, tear complexity, rim width, isolated versus concomitant ACLR, or medial- versus lateral-sided repair. There were no complications in the all-inside group, while there was a 10% rate of minor complications in the inside-out group (P = .49). CONCLUSION: Overall, satisfactory clinical outcomes are achievable at short-term to midterm follow-up with both inside-out and all-inside repair techniques of bucket-handle meniscal tears in rigorously matched patients with similar meniscal tear patterns.

Short- to mid-term outcomes of anatomic MCL reconstruction with Achilles tendon allograft after multiligament knee injury.

PURPOSE: Multiple techniques have been described in the literature for reconstruction of the medial collateral ligament. The purpose of this study is to describe functional outcome, range of motion, and knee stability following anatomic MCL reconstruction utilizing an Achilles tendon bone allograft after multiligament knee injury. METHODS: A comprehensive search of a single-hospital multiligament knee injury (MLKI) procedural database was conducted to identify all patients that underwent reconstruction of the MCL utilizing an Achilles tendon bone allograft and with 2-year clinical follow-up. Medical charts were retrospectively reviewed to determine each patient's knee dislocation (KD) grade, final range of motion, stability on clinical examination, and the incidence of complications and reoperations. KOOS, IKDC, and Marx scores were also collected. RESULTS: Thirty-two knees in 32 patients (21 males and 11 females) with a mean age of 30 years (range 15-51) were followed for an average of 40 months (range 28-87 months) following MCL reconstruction with Achilles tendon bone allograft. For patients with multiligament knee injuries, there were 14 KD-I (11 ACL/MCL; 3 MCL/PCL; 1 MCL/ACL/LCL; 1 MCL/PCL/LCL), 12 KD 3-M, and 3 KD-IV. One patient underwent isolated revision MCL reconstruction. At final follow-up, clinically significant valgus laxity was observed in only 1 patient (3%). All patients were able to achieve full extension of the knee and the average flexion was 121.1 ± 19.6. The average IKDC score was 67.6 ± 19.9 (range 27.7-98.9), the average KOOS score 77.1 ± 16.8 (range 31-100). The average Marx score was 4.9 (range 0-16, SD 5.2). Thirty-one of 32 (96%) patients reported being satisfied with results of the surgery. Knee dislocation grades were significantly correlated with post-operative outcome measures. CONCLUSION: In a series utilizing a modified Marx Achilles tendon, MCL reconstruction in the setting of MLKI demonstrated satisfactory clinical and functional outcomes, as well as patient satisfaction at short- to mid-term follow-up. Furthermore, knee dislocation grades were demonstrated to correlate with post-operative IKDC, KOOS, and Marx scores. LEVEL OF EVIDENCE: Type IV.

Individualizing the tibial tubercle to trochlear groove distance to patient specific anatomy improves sensitivity for recurrent instability.

PURPOSE: An initial episode of patellar instability poses a treatment challenge given the absence of a valid, reproducible, and universally applicable predictor of recurrence. Recently, a series of patellar instability ratios (PIRs) were described. Each ratio consisted of the traditional tibial tubercle to trochlear groove (TT-TG) distance normalized to patient-specific measures. The purpose of this study was to investigate the reliability and validity of these novel measures. METHODS: Eighty-seven patients experiencing a first-time lateral patellar dislocation were identified in a retrospective manner. Magnetic resonance imaging (MRI) studies obtained at the time of injury were reviewed. The TT-TG distance, patellar width (PW), trochlear width (TW), patellar length (PL), and trochlear length (TL) were obtained by two observers in a blinded, randomized fashion. Measurement reliability was assessed using intra-class correlation coefficients (ICCs). Patients were divided into those having a single dislocation (Group 1) and those experiencing recurrent instability (Group 2). The ability of the TT-TG distance and each PIR to predict recurrent instability was assessed by calculating odds ratios (ORs) with 95% confidence intervals (CIs). Sensitivity and specificity were also calculated for each measure. RESULTS: Excellent inter-rater agreement was observed with ICCs > 0.75 for all patellofemoral joint measurements obtained on MRI. The TT-TG distance alone was predictive of recurrent patellar instability with an OR of 8.9 (p < 0.001). However, the isolated TT-TG distance had the lowest sensitivity at 25.6%. Among ratios, a TT-TG/PL ≥ 0.5 was the most predictive of recurrent instability with an ORs of 6.1 (p = < 0.001). A TT-TG/TL ≥ 0.8 was also predictive of recurrence (OR 4.9, p = 0.027) and had the highest sensitivity of any measure at 94.9%. CONCLUSION: The results of the current study support the reproducibility and predictive ability of PIRs. While a TT-TG ≥ 20 mm was the strongest predictor of recurrent patellar instability, it was a relatively insensitive measure. Sensitivity may be improved by normalizing the TT-TG distance to patient-specific axial and sagittal plane patellofemoral measurements on MRI. Ultimately, PIRs are reproducible measures that may serve as an additional tool when clinically assessing the unstable patellofemoral joint. LEVEL OF EVIDENCE: III.

Effect of Vascular Injury on Functional Outcome in Knees with Multi-Ligament Injury: A Matched-Cohort Analysis.

BACKGROUND: Multi-ligament knee injury (MLKI) associated with knee dislocation can result in vascular injury. The purpose of this study was to compare knee function after MLKI between patients with a vascular injury requiring popliteal artery bypass grafting and patients without vascular involvement. Additionally, factors associated with poor knee function in patients who had MLKI with vascular injury were evaluated. METHODS: This retrospective study identified patients with an MLKI between 1992 and 2014. Each patient who had a concomitant vascular injury requiring bypass grafting (vascular cohort, n = 16; mean age, 30.3 years) was matched to 2 patients without a vascular injury (control cohort, n = 32; mean age, 31.4 years) on the basis of age, knee dislocation (KD) grade, and peroneal nerve status. Fifteen patients in the vascular cohort and 26 patients in the control cohort had an isolated knee injury. Functional outcomes were assessed with physical examination of range of motion and ligamentous stability as well as patient-reported outcome scores. RESULTS: The vascular cohort had a mean Lysholm score of 62.5 points (range, 16 to 100 points) and a mean International Knee Documentation Committee (IKDC) score of 59.7 points (range, 14.9 to 100 points) at a mean (and standard deviation) of 8.3 ± 5.0 years after surgery. The control cohort had a mean Lysholm score of 86.4 points (range, 51.0 to 100.0 points) and a mean IKDC score of 83.8 points (range, 35.6 to 100.0 points) at a mean of 6.0 ± 4.0 years. The vascular cohort had significantly lower Lysholm (p = 0.001) and IKDC (p = 0.002) scores than the control cohort. A body mass index (BMI) of >30 kg/m was predictive of lower IKDC (p = 0.0009) and Lysholm (p = 0.0008) scores. CONCLUSIONS: Patients who sustain an MLKI with an associated popliteal artery injury requiring bypass grafting have significantly lower knee function scores than patients without vascular involvement. This information can be used to help counsel patients with combined multiple ligament and popliteal artery injuries. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

WO3 and W Thermal Atomic Layer Etching Using "Conversion-Fluorination" and "Oxidation-Conversion-Fluorination" Mechanisms.

The thermal atomic layer etching (ALE) of WO3 and W was demonstrated with new "conversion-fluorination" and "oxidation-conversion-fluorination" etching mechanisms. Both of these mechanisms are based on sequential, self-limiting reactions. WO3 ALE was achieved by a "conversion-fluorination" mechanism using an AB exposure sequence with boron trichloride (BCl3) and hydrogen fluoride (HF). BCl3 converts the WO3 surface to a B2O3 layer while forming volatile WOxCly products. Subsequently, HF spontaneously etches the B2O3 layer producing volatile BF3 and H2O products. In situ spectroscopic ellipsometry (SE) studies determined that the BCl3 and HF reactions were self-limiting versus exposure. The WO3 ALE etch rates increased with temperature from 0.55 Å/cycle at 128 °C to 4.19 Å/cycle at 207 °C. W served as an etch stop because BCl3 and HF could not etch the underlying W film. W ALE was performed using a three-step "oxidation-conversion-fluorination" mechanism. In this ABC exposure sequence, the W surface is first oxidized to a WO3 layer using O2/O3. Subsequently, the WO3 layer is etched with BCl3 and HF. SE could simultaneously monitor the W and WO3 thicknesses and conversion of W to WO3. SE measurements showed that the W film thickness decreased linearly with number of ABC reaction cycles. W ALE was shown to be self-limiting with respect to each reaction in the ABC process. The etch rate for W ALE was ∼2.5 Å/cycle at 207 °C. An oxide thickness of ∼20 Å remained after W ALE, but could be removed by sequential BCl3 and HF exposures without affecting the W layer. These new etching mechanisms will enable the thermal ALE of a variety of additional metal materials including those that have volatile metal fluorides.

High Rate of Osteoarthritis After Osteochondritis Dissecans Fragment Excision Compared With Surgical Restoration at a Mean 16-Year Follow-up.

BACKGROUND: Osteochondritis dissecans (OCD) is a disorder of subchondral bone that causes adverse effects on the overlying cartilage and commonly affects the knee. The incidence of OCD and its long-term effect on the knee joint are controversial. Hypothesis/Purpose: The purpose of this study was to (1) evaluate the rate of osteoarthritis and knee arthroplasty in a population-based cohort of patients with OCD lesions treated operatively and (2) evaluate factors that may predispose patients to knee osteoarthritis and arthroplasty. The investigators hypothesized that OCD lesions diagnosed after skeletal maturity and treatment with fragment excision would be predictive of a diagnosis of osteoarthritis. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: The investigators identified 221 patients (mean ± SD age, 26.1 ± 13.6 years) with OCD lesions treated operatively between 1976 and 2010 and followed for 16.3 ± 11.4 years (mean ± SD) from diagnosis. Information related to the diagnosis, laterality of lesion, details of treatment, and progression to osteoarthritis was obtained from the medical record. Surgical treatment was classified as fragment excision, fragment preservation (lesion drilling and/or fragment fixation), or chondral defect grafting (osteochondral allograft or autograft). Factors predictive of osteoarthritis and arthroplasty were examined. RESULTS: There were 134 patients in the fragment excision group, 78 patients in the fragment preservation group, and 9 patients in the chondral defect grafting group. In the fragment excision group, the cumulative incidence of osteoarthritis was 12.0% at 5 years, 17.0% at 10 years, 26.0% at 15 years, 39.0% at 20 years, and 70% at 30 years. The cumulative incidence of arthroplasty was 2.0% at 5 years, 4.0% at 10 years, 4.0% at 15 years, 10.0% at 20 years, and 32.0% at 30 years. In the fragment preservation group, the cumulative incidence of osteoarthritis was 3.0% at 5 years, 7.0% at 10 years, 16.0% at 15 years, 25.0% at 20 years, and 51% at 30 years. The cumulative incidence of arthroplasty was 0.0% at 5 years, 0.0% at 10 years, 3.0% at 15 years, 6.0% at 20 years, and 11.0% at 30 years. No patients in the chondral defect grafting group developed osteoarthritis or underwent arthroplasty. Body mass index (BMI) greater than 25 kg/m2 (hazard ratio [HR] 3.3; 95% CI, 1.6-7.0), older age at diagnosis (HR 4.9; 95% CI, 1.8-17.3), and fragment excision (HR 2.3; 95% CI, 1.2-4.6) were predictive of osteoarthritis. CONCLUSION: OCD patients treated with fragment excision have a high rate of osteoarthritis and knee arthroplasty at long-term follow-up. In contrast, patients treated with fragment preservation or chondral defect grafting have lower rates of osteoarthritis and arthroplasty. BMI greater than 25 kg/m2, older age at diagnosis, and fragment excision were predictive of osteoarthritis.

Patellofemoral Arthritis After Lateral Patellar Dislocation: A Matched Population-Based Analysis.

BACKGROUND: The rate of patellofemoral arthritis after lateral patellar dislocation is unknown. Purpose/Hypothesis: The purpose of this study was to compare the risk of patellofemoral arthritis and knee arthroplasty between patients who experienced a lateral patellar dislocation and matched individuals without a patellar dislocation. Additionally, factors predictive of arthritis after patellar dislocation were examined. The hypothesis was that the rate of arthritis is likely higher among patients who experience a patellar dislocation compared with those who do not. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: In this study, 609 patients who had a first-time lateral patellar dislocation between 1990 and 2010 were compared with an age- and sex-matched cohort of patients who did not have a patellar dislocation. Medical records were reviewed to collect information related to the initial injury, recurrent dislocation, treatment, and progression to clinically significant patellofemoral arthritis (defined as symptoms with degenerative changes on patellar sunrise radiographs). Factors associated with arthritis (age, sex, recurrence, osteochondral injury, trochlear dysplasia) were examined. RESULTS: At a mean follow-up of 12.3 ± 6.5 years from initial dislocation, 58 patients (9.5%) in the dislocation cohort were diagnosed with patellofemoral arthritis, corresponding to a cumulative incidence of arthritis of 1.2% at 5 years, 2.7% at 10 years, 8.1% at 15 years, 14.8% at 20 years, and 48.9% at 25 years. In the control cohort, 8 patients (1.3%) were diagnosed with arthritis, corresponding to a cumulative incidence of arthritis of 0% at 5 years, 0% at 10 years, 1.3% at 15 years, 2.9% at 20 years, and 8.3% at 25 years. Therefore, patients who experienced a lateral patellar dislocation had a significantly higher risk of developing arthritis (hazard ratio [HR], 7.8; 95% CI, 3.9-17.6; P < .001) than individuals without a patellar dislocation. However, the risk of knee arthroplasty was similar between groups (HR, 2.8; 95% CI, 0.6-19.7; P = .2). Recurrent patellar dislocations (HR, 4.5; 95% CI, 1.6-12.6), osteochondral injury (HR, 11.3; 95% CI, 5.0-26.6), and trochlear dysplasia (HR, 3.6; 95% CI, 1.3-10.0) were associated with arthritis after patellar dislocation. CONCLUSION: Patellar dislocation is a significant risk factor for patellofemoral arthritis, as nearly half of patients have symptoms and radiographic changes consistent with arthritis at 25 years after lateral patellar dislocation. Osteochondral injury, recurrent patellar instability, and trochlear dysplasia are associated with the development of arthritis.

Molecular Structures and Ion Mobility Cross Sections: Analysis of the Effects of He and N2 Buffer Gas.

An empirically observed correlation between ion mobility cross sections in helium and nitrogen buffer gases was examined as a function of temperature, molecular size, and shape. Experimental cross sections were determined for tetraglycine, bradykinin, angiotensin 2, melittin, and ubiquitin at 300 K and in the range from 80 to 550 K on home-built instruments and calculated by the projection superposition approximation (PSA) method. The PSA was also used to predict cross sections for larger systems such as human pancreatic alpha-amylase, concanavalin, Pichia pastoris lysyl oxidase, and Klebsiella pneumoniae acetolactate synthase. The data show that the ratio of cross sections in helium and nitrogen depends significantly on the temperature of the buffer gas as well as the size and shape of the analyte ion. Therefore, the analysis of the data indicates that a simple formula that seeks to quantitatively relate the momentum transfer cross sections observed in two distinct buffer gases lacks a sound physical basis.

High-throughput measurement and classification of organic P in environmental samples.

Many types of organic phosphorus (P) molecules exist in environmental samples. Traditional P measurements do not detect these organic P compounds since they do not react with colorimetric reagents. Enzymatic hydrolysis (EH) is an emerging method for accurately characterizing organic P forms in environmental samples. This method is only trumped in accuracy by Phosphorus-31 Nuclear Magnetic Resonance Spectroscopy ((31)P-NMR)--a method that is expensive and requires specialized technical training. We have adapted an enzymatic hydrolysis method capable of measuring three classes of phosphorus (monoester P, diester P and inorganic P) to a microplate reader system. This method provides researchers with a fast, accurate, affordable and user-friendly means to measure P species in soils, sediments, manures and, if concentrated, aquatic samples. This is the only high-throughput method for measuring the forms and enzyme-lability of organic P that can be performed in a standard laboratory. The resulting data provides insight to scientists studying system nutrient content and eutrophication potential.